JP2004295528A - Printer, printing system, and server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the security of printing data by permitting printing of the printing data by only a printer provided in a specified area of printers which receive the printing data. <P>SOLUTION: Each of printers A-D connected to a network prepares a dedicated public key for its exclusive use and a wide-range public key to be shared with printers located in a certain specified area, and reports the exclusive public key and the wide-range public key to a server 20. The server 20 encrypts printing data D05, when the data permit printing by only a specified printer (e.g., the printer A), by use of the dedicated public key to the printer A followed by transmitting, and encrypts the printing data D05, when the data permit printing by any printers located in the specified area (e.g., printers A-C), by use of the wide-area public key of the area concerned followed by transmitting. The printing data D05 encrypted with the wide-range public key can be printed by the printers A-C located in the specified area, but not by printers out of this area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【数２】

【００４７】
ここで、ＸはプリンタのＸ方向の位置、ＹはプリンタのＹ方向の位置、Ｘ０はこの空間のＸ軸の原点からメッシュのＸ軸がどれだけオフセットしているかを示す量、Ｙ０はこの空間Ｙ軸の原点からメッシュのＹ軸がどれだけオフセットしているかを示す量、Ｗは１つの領域のＸ方向の幅、Ｈは１つの領域のＹ方向の幅である。すなわち、図４に示すように、プリンタが位置する仮想上の空間の原点（０、０）と、複数の領域から構成されているメッシュの原点には、Ｘ０、Ｙ０分のずれが存在する場合もあるのである。また、各プリンタＡ〜Ｄは、Ｘ０、Ｙ０、Ｗ及びＨについては、サーバ２０から各プリンタに事前に通知されているものとする。或いは、各ユーザが各プリンタに予め設定してあるものとする。
【００４８】
続いて、プリンタＡ〜Ｄは、Ｘ方向の中央値Ｘｍと、Ｙ方向の中央値Ｙｍと、１つの領域の大きさを特定する情報（Ｗ、Ｈ）とを用いて、広域パスフレーズＷＰを生成する。本実施形態においては、Ｘ方向の中央値Ｘｍの後ろに、Ｙ方向の中央値Ｙｍを結合し、その後ろにＸ方向の領域の幅（ここでは２０ｋｍ）を結合し、その後ろにＹ方向の領域の幅（ここでは２０ｋｍ）を結合することにより、広域パスフレーズＷＰを生成する。そして、この広域パスフレーズＷＰを用いて、公開鍵暗号法により公開鍵（広域公開鍵）と秘密鍵（広域秘密鍵）を生成し、この専用公開鍵をサーバ２０に通知しておく。但し、広域公開鍵は保存することなく、破棄する。
【００４９】
なお、広域パスフレーズＷＰを生成手法は、この例に限られるものではない。要は、同じ領域に属するプリンタの間では同じ広域パスフレーズＷＰが用いられ、異なる領域に属するプリンタとの間では異なる広域パスフレーズＷＰが用いられるようにすればよい。
【００５０】
サーバ２０に通知された専用公開鍵と広域公開鍵とは、サーバ２０のハードディスク７６に形成された公開鍵テーブルＴＢ１０に格納される。図７は、本実施形態に係る公開鍵テーブルＴＢ１０の構成を示す図である。
【００５１】
この図７に示すように、公開鍵テーブルＴＢ１０では、各プリンタ毎に、広域公開鍵と専用公開鍵とが格納され、保持される。図７から分かるように、プリンタＡ〜Ｃの広域公開鍵がともに「ＰＫＥＹ１」であり、共通になる。なぜなら、図６に示したように、これらのプリンタＡ〜Ｃの間では、Ｘ方向の中央値ＸｍとＹ方向の中央値Ｘｍが同じになるので、広域公開鍵を生成する際に使用する広域パスフレーズＷＰが同じになるからである。一方、プリンタＤは、これらプリンタＡ〜Ｃの間とＸ方向の中央値Ｘｍが異なるので、広域公開鍵を生成する際に使用する広域パスフレーズＷＰも異なるものとなる。このため、プリンタＤの広域公開鍵は、プリンタＡ〜Ｃと異なるものとなる。
【００５２】
これに対して、各プリンタＡ〜Ｄの専用公開鍵は、各プリンタＡ〜Ｄ毎に異なるものとなる。なぜなら、図５に示したように、専用公開鍵を生成する際に使用する専用パスフレーズＰＰは、各プリンタＡ〜Ｄ毎に異なるものとなるからである。図７の例では、各プリンタＡ〜Ｄに対応して、それぞれ、専用公開鍵「ＰＫＥＹ１０」、「ＰＫＥＹ１１」、「ＰＫＥＹ１２」、「ＰＫＥＹ１３」が格納されている。
【００５３】
なお、このようにハードディスク７８の公開鍵テーブルＴＢ１０に公開鍵を格納することにより、サーバ２０の電源がオフされて再び電源が投入された場合でも、それ以前に取得した公開鍵をそのままハードディスク７８から読み出して使用することができるようになっている。
【００５４】
このようにサーバ２０が各プリンタＡ〜Ｄの専用公開鍵と広域公開鍵とを取得した後に、例えば、専用公開鍵「ＰＫＥＹ１０」を送信したときと同じ位置にあるプリンタＡに対してのみ印刷を認める印刷データを送信したい場合には、図８に示すように、印刷データＤ０５を生成した後、公開鍵テーブルＴＢ１０からプリンタＡの専用公開鍵「ＰＫＥＹ１０」を読み出して、この専用公開鍵「ＰＫＥＹ１０」を用いて印刷データＤ０５を暗号化し、暗号化印刷データＤ１０を生成する。そして、サーバ２０はネットワーク１０を介して、この暗号化印刷データＤ１０をプリンタＡに送信する。
【００５５】
プリンタＡが専用公開鍵「ＰＫＥＹ１０」を生成したときと同じ位置にあれば、再び専用パスフレーズＰＰを用いて公開鍵暗号法により専用秘密鍵を生成したとしても、同じ専用秘密鍵が生成される。すなわち、専用公開鍵「ＰＫＥＹ１０」で暗号化された印刷送信用データＤ１０を復号することのできる専用秘密鍵を、再び得ることができる。このため、プリンタＡは、この専用秘密鍵で暗号化印刷データＤ１０を復号し、印刷データＤ０５を取得し、この印刷データＤ０５に基づく印刷を行うことができる。
【００５６】
もし、プリンタＡが別の場所に移動されていた場合には、図５に示した専用パスフレーズＰＰにおけるＸ方向の位置とＹ方向の位置が異なるものになっているため、この専用パスフレーズＰＰを用いて公開鍵暗号法により専用秘密鍵を生成したとしても、異なる専用秘密鍵が生成される。すなわち、専用公開鍵「ＰＫＥＹ１０」で暗号化された印刷送信用データＤ１０を復号することのできる専用秘密鍵を、得ることができない。このため、プリンタＡは、暗号化印刷データＤ１０に基づく印刷を行うことができない。
【００５７】
これに対して、サーバ２０が、例えばプリンタＡ〜Ｃに対してのみ印刷を認める印刷データを送信したい場合には、図９に示すように、印刷データＤ０５を生成した後、公開鍵テーブルＴＢ１０からプリンタＡ〜Ｃに共通である広域公開鍵「ＰＫＥＹ１」を読み出して、この広域公開鍵「ＰＫＥＹ１」を用いて印刷データＤ０５を暗号化し、暗号化印刷データＤ１０を生成する。そして、サーバ２０はネットワーク１０を介して、この暗号化印刷データＤ１０をプリンタＡ〜Ｃに送信する。
【００５８】
プリンタＡ〜Ｃが専用公開鍵「ＰＫＥＹ１」を生成したときと同じ領域内にあれば、再び広域パスフレーズＷＰを用いて公開鍵暗号法により広域秘密鍵を生成したとしても、同じ広域秘密鍵が生成される。すなわち、広域公開鍵「ＰＫＥＹ１」で暗号化された印刷送信用データＤ１０を復号することのできる広域秘密鍵を、再び得ることができる。このため、プリンタＡ〜Ｃは、それぞれ、この広域秘密鍵で暗号化印刷データＤ１０を復号し、印刷データＤ０５を取得し、この印刷データＤ０５に基づく印刷を行うことができる。
【００５９】
もし、これら３台のプリンタのうち、例えばプリンタＡが別の領域に移動されていた場合には、図６に示した広域パスフレーズＷＰにおけるＸ方向の中央値ＸｍとＹ方向の中央値Ｙｍのうちの少なくとも一方が、広域公開鍵「ＰＫＥＹ１」を生成したときと異なるものになっているため、この広域パスフレーズＷＰを用いて公開鍵暗号法により広域秘密鍵を生成したとしても、異なる広域秘密鍵が生成される。すなわち、広域公開鍵「ＰＫＥＹ１」で暗号化された印刷送信用データＤ１０を復号することのできる広域秘密鍵を、得ることができない。このため、プリンタＡは、暗号化印刷データＤ１０に基づく印刷を行うことができない。
【００６０】
以上が本実施形態に係る印刷システムにおける専用印刷と広域印刷の処理概念であるが、次に、このような処理を実現するために、サーバ２０及びプリンタＡ〜Ｄで実行される各処理について詳しく説明する。
【００６１】
図１０は、サーバ２０で実行される公開鍵要求処理を説明するフローチャートである。この公開鍵要求処理は、サーバのＲＯＭ６８又はハードディスク７６に格納されている公開鍵要求プログラムをＣＰＵ６４が読み込んで実行することにより実現される処理である。ここでは、サーバ２０からプリンタＡに公開鍵を要求する場合を想定して説明する。
【００６２】
図１０に示すように、この公開鍵要求処理においては、まずサーバ２０は、ネットワーク１０を介して、プリンタＡに接続する（ステップＳ１００）。本実施形態においては、サーバ２０は、プリンタＡのネットワークアドレスを指定することにより、サーバ２０とプリンタＡとの間の接続を確立する。
【００６３】
次に、サーバ２０は、プリンタＡへ認証情報を送信する（ステップＳ１０２）。本実施形態においては、この認証情報として、サーバを特定するためのサーバＩＤと、パスワードとの組み合わせを用いている。したがって、サーバ２０は、サーバＩＤとパスワードとを、プリンタＡへ送信する。
【００６４】
これに続いて、サーバ２０は、プリンタＡから認証が受け入れられたか否かを示す認証結果を受信するので、この認証結果に基づいて、プリンタＡで認証が認められたかどうかを判断する（ステップＳ１０４）。認証が認められなかった場合（ステップＳ１０４：Ｎｏ）には、この公開鍵要求処理を終了する。
【００６５】
一方、認証が認められた場合（ステップＳ１０４：Ｙｅｓ）には、サーバ２０は、公開鍵取得要求をプリンタＡへ送信する（ステップＳ１０６）。そして、プリンタＡから、プリンタＡの専用公開鍵を受信したかどうかを判断する（ステップＳ１０８）。プリンタＡから専用公開鍵を受信していない場合（ステップＳ１０８：Ｎｏ）には、このステップＳ１０８を繰り返して待機する。
【００６６】
一方、プリンタＡから専用公開鍵を受信した場合（ステップＳ１０８：Ｙｅｓ）には、この専用公開鍵を公開鍵テーブルＴＢ１０（図７参照）に格納する（ステップＳ１１０）。
【００６７】
次に、サーバ２０は、プリンタＡから、プリンタＡの広域公開鍵を受信したかどうかを判断する（ステップＳ１１２）。プリンタＡから広域公開鍵を受信していない場合（ステップＳ１１２：Ｎｏ）には、このステップＳ１１２を繰り返して待機する。
【００６８】
一方、プリンタＡから広域公開鍵を受信した場合（ステップＳ１１２：Ｙｅｓ）には、この広域公開鍵を公開鍵テーブルＴＢ１０（図７参照）に格納する（ステップＳ１１４）。
【００６９】
この公開鍵テーブルＴＢ１０に、取得した専用公開鍵と広域公開鍵とを格納することにより、本実施形態に係る公開鍵要求処理は終了する。
【００７０】
次に、図１１及び図１２に基づいて、サーバ２０の公開鍵要求処理に対応して、プリンタＡ〜Ｄで実行される公開鍵送信処理について説明する。この図１１及び図１２は、プリンタＡ〜Ｄで実行される公開鍵送信処理を説明するフローチャートである。この公開鍵送信処理は、プリンタＡ〜ＤのＲＯＭ４４に格納されている公開鍵送信プログラムをＣＰＵ４０が読み込んで実行することにより実現される処理である。ここでも上述と同様に、サーバ２０からプリンタＡに公開鍵が要求された場合を想定して説明する。
【００７１】
図１１に示すように、まず、プリンタＡは、サーバ２０と接続を確立する（ステップＳ１２０）。これは上述したサーバ２０側のステップＳ１００に対応している。続いて、プリンタＡは、サーバ２０から認証情報を受信したかどうかを判断する（ステップＳ１２２）。認証情報を受信していない場合（ステップＳ１２２：Ｎｏ）には、このステップＳ１２２の処理を繰り返して待機する。
【００７２】
一方、認証情報をサーバ２０から受信した場合（ステップＳ１２２：Ｙｅｓ）には、その認証情報がこのプリンタＡに予め登録してある認証情報と一致するかどうかを判断する（ステップＳ１２４）。具体的には、上述したように、サーバ２０からサーバＩＤとパスワードが認証情報として送信されてくるので、このサーバＩＤとパスワードが、このプリンタＡに予め登録されているサーバＩＤとパスワードと一致するかどうかを判断する。
【００７３】
認証情報が一致しなかった場合（ステップＳ１２４：Ｎｏ）には、プリンタＡはサーバ２０に、認証が受け入れられなかった旨の認証結果を送信し（ステップＳ１２６）、この公開鍵送信処理を終了する。一方、認証が一致した場合（ステップＳ１２４：Ｙｅｓ）には、プリンタＡはサーバ２０に、認証が受け入れられた旨の認証結果を送信する（ステップＳ１２８）。
【００７４】
次に、プリンタＡは、サーバ２０から公開鍵取得要求を受信したかどうかを判断する（ステップＳ１３０）。この公開鍵取得要求を受信していない場合（ステップＳ１３０：Ｎｏ）には、このステップＳ１３０の処理を繰り返して待機する。
【００７５】
一方、サーバ２０から公開鍵取得要求を受信した場合（ステップＳ１３０：Ｙｅｓ）には、プリンタＡは、このプリンタＡの機器固有情報を取得する（ステップＳ１３２）。ここで、機器固有情報とは、このプリンタＡに関して、固有に割り当てられている識別情報であり、例えば、プリンタＡの製造シリアルナンバー、ＭＡＣアドレス等がある。
【００７６】
次に、プリンタＡは、位置検出部５４から、その時点におけるプリンタＡのプリンタ位置情報を取得する（ステップＳ１３４）。このようにプリンタ位置情報をその都度、位置検出部５４から取得することとしているのは、プリンタＡが別の場所に移動された場合には、その移動後の位置情報を用いて公開鍵（専用公開鍵、及び、広域公開鍵）を生成するようにするためである。
【００７７】
次に、図１２に示すように、プリンタＡは、機器固有情報とプリンタ位置情報とを用いて専用パスフレーズＰＰを作成する（ステップＳ１３６）。この専用パスフレーズＰＰの作成手法は種々のものが考えられるが、本実施形態においては、図５を用いて説明したように、単純に、機器固有情報の後ろに、プリンタ位置情報のＸ方向の位置とＹ方向の位置とを、つなげることにより、専用パスフレーズＰＰを作成する。なお、専用パスフレーズＰＰは、これら機器固有情報及びプリンタ位置情報以外のデータを含んでいてもよい。
【００７８】
次に、プリンタＡは、作成した専用パスフレーズＰＰを用いて、公開鍵暗号法により、専用公開鍵と専用秘密鍵とを生成する（ステップＳ１３８）。公開鍵暗号法では、使用するパスフレーズが同じであれば、再び、公開鍵（専用公開鍵）と秘密鍵（専用秘密鍵）とを生成しても、同じものが生成されるという性質を有している。続いて、プリンタＡは、この生成した専用公開鍵と専用秘密鍵のうち、専用公開鍵のみをサーバ２０に送信する（ステップＳ１４０）。なお、秘密鍵（専用秘密鍵）は保存されることなく破棄される。
【００７９】
次に、プリンタＡは、プリンタ位置情報を用いて広域パスフレーズＷＰを作成する（ステップＳ１４２）。この広域パスフレーズＷＰの作成手法は種々のものが考えられるが、本実施形態においては、図６を用いて説明したように、プリンタＡが属する領域のＸ方向の中央値ＸｍとＹ方向の中央値Ｙｍの後ろに、各領域のＸ方向の幅とＹ方向の幅とを結合することにより、広域パスフレーズＷＰを作成する。なお、広域パスフレーズＷＰは、同一の領域に属するプリンタの間で共通になるものであれば、この中央値以外のデータを含んでいてもよい。さらには、同一の領域に属するプリンタの間で共通になるものであれば、この広域パスフレーズＷＰをこの中央値以外のもので構成するようにしても良い。
【００８０】
次に、プリンタＡは、作成した広域パスフレーズＷＰを用いて、公開鍵暗号法により、広域公開鍵と広域秘密鍵とを生成する（ステップＳ１４４）。公開鍵暗号法では、使用するパスフレーズが同じであれば、再び、公開鍵（広域公開鍵）と秘密鍵（広域秘密鍵）とを生成しても、同じものが生成されるという性質を有している。続いて、プリンタＡは、この生成した広域公開鍵と広域秘密鍵のうち、広域公開鍵のみをサーバ２０に送信する（ステップＳ１４６）。なお、秘密鍵（広域秘密鍵）は保存されることなく破棄される。これにより、本実施形態に係る公開鍵送信処理が終了する。
【００８１】
次に、サーバ２０が特定の位置にある特定の１つのプリンタに印刷を実行させたいときに、その印刷データをそのプリンタに送信する場合のサーバ２０の処理について説明する。
【００８２】
図１３は、サーバ２０で実行される専用印刷要求処理を説明するフローチャートである。この専用印刷要求処理は、サーバのＲＯＭ６８又はハードディスク７６に格納されている専用印刷要求プログラムをＣＰＵ６４が読み込んで実行することにより実現される処理である。ここでは、サーバ２０からプリンタＡ対してのみ印刷を要求する場合を想定して説明する。
【００８３】
この図１７に示すように、サーバ２０は、ユーザの印刷要求に基づいて、印刷データＤ０５を作成する（ステップＳ１５０）。この印刷データＤ０５は、プリンタＡが通常のプリンタである場合に、印刷を実際に行うのに必要となるデータである。
【００８４】
次に、サーバ２０は、ハードディスク７６の公開鍵テーブルＴＢ１０から、プリンタＡの専用公開鍵「ＰＫＥＹ１０」を読み出す（ステップＳ１５２）。続いて、サーバ２０は、プリンタＡの専用公開鍵「ＰＫＥＹ１０」を用いて、印刷データＤ０５を暗号化して、印刷送信用データＤ１０を生成する（ステップＳ１５４）。なお、印刷送信用データＤ１０は、印刷データＤ０５以外のデータを含んでいてもよい。
【００８５】
次に、サーバ２０は、この暗号化した印刷送信用データＤ１０を、プリンタＡに送信する（ステップＳ１５６）。具体的には、プリンタＡのネットワークアドレスを指定して、ネットワーク１０に印刷送信用データＤ１０を送出する。
【００８６】
次に、サーバ２０は、プリンタＡから印刷結果情報を受信したかどうかを判断する（ステップＳ１５８）。印刷結果情報を受信していない場合（ステップＳ１５８：Ｎｏ）には、このステップＳ１５８の処理を繰り返して待機する。一方、印刷結果情報を受信した場合（ステップＳ１５８：Ｙｅｓ）には、その印刷結果情報が印刷完了通知であるかどうかを判断する（ステップＳ１６０）。
【００８７】
この印刷結果情報が印刷完了通知である場合（ステップＳ１６０：Ｙｅｓ）には、プリンタＡで印刷が正常に終了したことを意味しているので、このサーバ２０のユーザにプリンタＡで印刷が完了した旨を通知する（ステップＳ１６２）。一方、受信した印刷結果情報が印刷完了通知でない場合（ステップＳ１６０：Ｎｏ）には、その印刷結果情報が解読不能通知であるかどうかを判断する（ステップＳ１６４）。
【００８８】
印刷結果情報が解読不能通知である場合（ステップＳ１６４：Ｙｅｓ）には、ユーザに、プリンタＡで印刷送信用データの復号ができなかったため、印刷が行われなかった旨を通知する（ステップＳ１６６）。一方、印刷結果情報が解読不能通知でない場合（ステップＳ１６４：Ｎｏ）には、その他の何らかのエラーであると考えられるので、ユーザに、そのエラーの種類に応じた通知を行う（ステップＳ１６８）。
【００８９】
これらステップＳ１６２、ステップＳ１６６、及び、ステップＳ１６８の通知により、このサーバ２０における専用印刷要求処理は終了する。
【００９０】
次に、サーバ２０が、ある領域内にあるプリンタに印刷を実行させたいときに、その印刷データをそれらのプリンタに送信する場合のサーバ２０の処理について説明する。
【００９１】
図１４は、サーバ２０で実行される広域印刷要求処理を説明するフローチャートである。この広域印刷要求処理は、サーバ２０のＲＯＭ６８又はハードディスク７６に格納されている広域印刷要求プログラムをＣＰＵ６４が読み込んで実行することにより実現される処理である。ここでは、サーバ２０からプリンタＡ〜Ｃに対して印刷配信をする場合を想定して説明する。
【００９２】
この図１４に示すように、サーバ２０は、ユーザの印刷要求に基づいて、印刷データＤ０５を作成する（ステップＳ２００）。この印刷データＤ０５は、プリンタＡ〜Ｃが通常のプリンタである場合に、印刷を実際に行うのに必要となるデータである。
【００９３】
次に、サーバ２０は、ハードディスク７６の公開鍵テーブルＴＢ１０から、プリンタＡ〜Ｃに共通の広域公開鍵「ＰＫＥＹ１」を読み出す（ステップＳ２０２）。具体的には、公開鍵テーブルＴＢ１０から、印刷データＤ０５の印刷を許可する領域にある１台のプリンタ（例えば、図７のプリンタＡ）の広域公開鍵「ＰＫＥＹ１」を読み出す。どのプリンタの広域公開鍵を読み出すかは、任意である。なお、１つの領域内に位置するプリンタであれば、広域公開鍵は共通であるので、どれか１台のプリンタの広域公開鍵を読み出せば足りる。換言すれば、同一の広域公開鍵のプリンタは、同一の領域内に位置していることになる。
【００９４】
続いて、サーバ２０は、プリンタＡ〜Ｃに共通の広域公開鍵「ＰＫＥＹ１」を用いて、印刷データＤ０５を暗号化して、印刷送信用データＤ１０を生成する（ステップＳ２０４）。なお、印刷送信用データＤ１０は、印刷データＤ０５以外のデータを含んでいてもよい。
【００９５】
次に、サーバ２０は、この暗号化した印刷送信用データＤ１０を、その領域にあるすべてのプリンタに送信する（ステップＳ２０６）。この例では、プリンタＡ〜Ｃのネットワークアドレスをそれぞれ指定して、ネットワーク１０に印刷送信用データＤ１０を送出する。但し、プリンタＡ〜Ｃに共通の同報通信アドレスがあるような場合には、同報通信により送信するようにしてもよい。
【００９６】
次に、サーバ２０は、プリンタＡ〜Ｃのいずれかのプリンタから印刷結果情報を受信したかどうかを判断する（ステップＳ２０８）。どのプリンタからも印刷結果情報を受信していない場合（ステップＳ２０８：Ｎｏ）には、このステップＳ２０８の処理を繰り返して待機する。一方、いずれかのプリンタから印刷結果情報を受信した場合（ステップＳ２０８：Ｙｅｓ）には、その印刷結果情報が印刷完了通知であるかどうかを判断する（ステップＳ２１０）。
【００９７】
この印刷結果情報が印刷完了通知である場合（ステップＳ２１０：Ｙｅｓ）には、そのプリンタでは、印刷が正常に終了したことを意味しているので、このサーバ２０のユーザに、該当するプリンタでは印刷が完了した旨を通知する（ステップＳ２１２）。一方、受信した印刷結果情報が印刷完了通知でない場合（ステップＳ２１０：Ｎｏ）には、その印刷結果情報が解読不能通知であるかどうかを判断する（ステップＳ２１４）。
【００９８】
印刷結果情報が解読不能通知である場合（ステップＳ２１４：Ｙｅｓ）には、ユーザに、該当するプリンタでは印刷送信用データの復号ができなかったため、印刷が行われなかった旨を通知する（ステップＳ２１６）。一方、印刷結果情報が解読不能通知でない場合（ステップＳ２１４：Ｎｏ）には、その他の何らかのエラーであると考えられるので、ユーザに、そのエラーの種類に応じた通知を行う（ステップＳ２１８）。
【００９９】
これらステップＳ２１２、ステップＳ２１６、及び、ステップＳ２１８の通知の後、ステップＳ２０６で印刷送信用データＤ１０を送信したすべてのプリンタから、印刷結果情報を受信したかどうかを判断する（ステップＳ２２０）。すべてのプリンタから印刷結果情報を受信していない場合（ステップＳ２２０：Ｎｏ）、すなわち、印刷結果情報を受信していないプリンタがまだ残っている場合には、上述したステップＳ２０８からを繰り返す。
【０１００】
一方、すべてのプリンタから印刷結果情報を受信した場合（ステップＳ２２０：Ｙｅｓ）には、このサーバ２０における広域印刷要求処理は終了する。
【０１０１】
次に、図１５及び図１６に基づいて、サーバ２０の専用印刷要求処理及び広域印刷要求処理に対応して、プリンタＡ〜Ｄで実行される印刷実行処理について説明する。図１５及び図１６は、プリンタＡ〜Ｄで実行される印刷実行処理を説明するフローチャートである。この印刷実行処理は、プリンタＡ〜ＤのＲＯＭ４４に格納されている印刷実行プログラムをＣＰＵ４０が読み込んで実行することにより実現される処理である。ここでも上述と同様に、サーバ２０からプリンタＡに印刷が要求された場合を想定して説明する。
【０１０２】
図１５に示すように、プリンタＡは、印刷送信用データＤ１０をネットワーク１０から受信したかどうかを判断する（ステップＳ２７０）。何ら印刷送信用データＤ１０を受信していない場合（ステップＳ２７０：Ｎｏ）には、このステップＳ２７０の処理を繰り返して待機する。
【０１０３】
一方、印刷送信用データＤ１０を受信した場合（ステップＳ２７０：Ｙｅｓ）には、プリンタＡは自らの機器固有情報を取得する（ステップＳ２７２）。続いて、プリンタＡは、位置検出部５４から、その時点におけるプリンタＡのプリンタ位置情報を取得する（ステップＳ２７４）。このようにプリンタ位置情報を、その都度、位置検出部５４から取得することとしているのは、プリンタが別の場所に移動された場合には、このプリンタがサーバ２０のユーザの意図しない場所に設置されている可能性や、意図した領域内に位置していない可能性があり、このような場合にはプリンタで印刷が行われないようにするためである。
【０１０４】
次に、プリンタＡは、機器固有情報とプリンタ位置情報とに基づいて、専用パスフレーズＰＰを作成する（ステップＳ２７６）。この専用パスフレーズＰＰの作成手法は、上述した公開鍵送信処理におけるステップＳ１３６と同じ手法である必要がある。なぜなら、専用パスフレーズＰＰが異なると、サーバに送信した専用公開鍵で暗号化された印刷送信用データＤ１０を、専用秘密鍵で復号できなくなってしまうからである。
【０１０５】
次に、プリンタＡは、専用パスフレーズＰＰを用いて、公開鍵暗号法により専用公開鍵と専用秘密鍵とを生成する（ステップＳ２７８）。続いて、プリンタＡは、生成された専用秘密鍵を用いて、受信した印刷送信用データＤ１０を復号して、印刷データＤ０５を取得する（ステップＳ２８０）。
【０１０６】
次に、プリンタＡは、専用秘密鍵を用いて印刷送信用データＤ１０の復号ができたかどうかを判断する（ステップＳ２８２）。復号ができた場合（ステップＳ２８２：Ｙｅｓ）には、得られた印刷データＤ０５に基づいて、印刷エンジン５２を駆動した印刷を実行する（ステップＳ２８４）。具体的には、印刷データＤ０５の言語解釈を行い、印刷エンジン５２に適合した印刷要求データを生成する。そして、この印刷要求データを印刷エンジン５２に送信することにより、印刷エンジン５２で印刷用紙等に印刷が行われる。
【０１０７】
この印刷が正常に完了した時点で、プリンタＡは、印刷が正常に終了した旨の印刷完了通知を、印刷結果情報として、サーバ２０に送信する（ステップＳ２８６）。そして、上述したステップＳ２７０の処理に戻る。
【０１０８】
これに対して、ステップＳ２８２において、印刷送信用データＤ１０の復号ができなかったと判断した場合（ステップＳ２８２：Ｎｏ）には、図１６に示すように、プリンタＡは、プリンタ位置情報に基づいて、広域パスフレーズＷＰを作成する（ステップＳ２９０）。この広域パスフレーズＷＰの作成手法は、上述した公開鍵送信処理におけるステップＳ１４２と同じ手法である必要がある。なぜなら、広域パスフレーズＷＰが異なると、サーバ２０に送信した広域公開鍵で暗号化された印刷送信用データＤ１０を、広域秘密鍵で復号できなくなってしまうからである。
【０１０９】
次に、プリンタＡは、広域パスフレーズＷＰを用いて、公開鍵暗号法により広域公開鍵と広域秘密鍵とを生成する（ステップＳ２９２）。続いて、プリンタＡは、生成された広域秘密鍵を用いて、受信した印刷送信用データＤ１０を復号して、印刷データＤ０５を取得する（ステップＳ２９４）。
【０１１０】
次に、プリンタＡは、広域秘密鍵を用いて印刷送信用データＤ１０の復号ができたかどうかを判断する（ステップＳ２９６）。復号ができた場合（ステップＳ２９６：Ｙｅｓ）には、得られた印刷データＤ０５に基づいて、印刷エンジン５２を駆動した印刷を実行する（ステップＳ２９８）。具体的には、印刷データＤ０５の言語解釈を行い、印刷エンジン５２に適合した印刷要求データを生成する。そして、この印刷要求データを印刷エンジン５２に送信することにより、印刷エンジン５２で印刷用紙等に印刷が行われる。
【０１１１】
この印刷が正常に完了した時点で、プリンタＡは、印刷が正常に終了した旨の印刷完了通知を、印刷結果情報として、サーバ２０に送信する（ステップＳ３００）。そして、上述したステップＳ２７０の処理に戻る。
【０１１２】
一方、上述したステップＳ２９６で、広域秘密鍵を用いて印刷送信用データＤ１０の復号ができなかったと判断した場合（ステップＳ２９６：Ｎｏ）には、解読不能通知を印刷結果情報として、サーバ２０に送信する（ステップＳ３０２）。そして、上述したステップＳ２７０の処理に戻る。
【０１１３】
以上のように、本実施形態に係る印刷システムによれば、サーバ２０は、専用公開鍵を用いて暗号化して送信した印刷送信用データＤ１０の印刷をできるプリンタを、プリンタ位置情報に基づいて限定することができるので、サーバ２０のユーザが意図していない位置にあるプリンタで印刷が行われしまうのを回避することができる。例えば、プリンタＡが別の場所に移動されたが、ネットワーク１０内におけるプリンタＡのネットワークアドレスは変更されていない場合に、サーバ２０から誤って印刷送信用データＤ１０をこのプリンタＡに送信してしまっても、プリンタＡではプリンタ位置情報が変更されているため、ステップＳ２７６で作成される専用パスフレーズＰＰが移動前と異なったものになる。このため、この専用パスフレーズＰＰを用いて生成された専用秘密鍵を用いても、印刷送信用データＤ１０の復号はできず、プリンタＡでは印刷が行われない。このため、印刷データＤ０５のセキュリティを高めることができる。
【０１１４】
一方、プリンタＡ〜Ｄ側においても、本来であればこのプリンタＡ〜Ｄで印刷する権限のない者が、印刷データＤ０５をこれらプリンタＡ〜Ｄに送信して、大量の印刷をプリンタＡ〜Ｄに実行させてしまうのを回避することができる。例えば、何らかの理由で、プリンタＡのネットワークアドレスを第三者が知得して、このプリンタＡに印刷送信用データＤ１０を送信しようとしても、このプリンタＡの専用公開鍵を取得することができない。もし、このユーザが異なる専用公開鍵で印刷データＤ０５を暗号化して印刷送信用データを生成したり、暗号化しないで印刷送信用データを生成したりして、プリンタＡに印刷送信用データを送信したとしても、印刷実行処理のステップＳ２８２及びステップＳ２９６で復号できないと判断されるので、プリンタＡに印刷を実行させることができなくなる。このため、プリンタＡ〜Ｄ自体のセキュリティを高めることができる。
【０１１５】
また、本実施形態においては、専用パスフレーズＰＰには機器固有情報も含めることとしたので、何らかの理由により第三者が、プリンタＡ〜Ｄの位置を知得したとしても、プリンタＡ〜Ｄの機器固有情報が分からなければ、プリンタＡ〜Ｄで使用されている専用パスフレーズＰＰを特定することができない。このため、正当な権限なき第三者がプリンタＡ〜Ｄで印刷を実行する可能性を、極めて低いものとすることができる。
【０１１６】
また、本実施形態に係る印刷システムによれば、サーバ２０は、複数のプリンタに送信した印刷送信用データＤ１０の印刷ができるプリンタの範囲を、所定の領域に制限することができる。すなわち、本実施形態の例では、所定の領域内にあるプリンタＡ〜Ｃのみが印刷できるようにするために、印刷データＤ０５をこれらプリンタＡ〜Ｃに共通の広域公開鍵「ＰＫＥＹ１０」で暗号化して、印刷送信用データＤ１０を生成した。このため、これらプリンタＡ〜Ｃがこの領域内に位置している限り、この印刷送信用データＤ１０を復号することができ、印刷することができる。すなわち、印刷送信用データＤ１０を受信した際に、ステップＳ２９０において、ステップＳ１４２で生成したのと同じ広域パスフレーズＷＰが生成されるので、ステップＳ１４２で生成したのと同じ広域秘密鍵が生成される。この広域秘密鍵を用いれば、受信した印刷送信用データＤ１０を復号することができる。
【０１１７】
もし、例えば、プリンタＡが別の領域に移動した場合には、プリンタＡのネットワークアドレスが変更されていなければ、プリンタＡはこの印刷送信用データＤ１０を受信することはできる。しかし、プリンタ位置情報が広域公開鍵を生成したときと異なることとなるので、印刷送信用データＤ１０を受信した際に、ステップＳ２９０において、ステップＳ１４２で生成した広域パスフレーズＷＰと同じ広域パスフレーズＷＰを得ることができない。このため、ステップＳ１４４で生成した広域秘密鍵と異なる広域秘密鍵が生成されてしまう。この結果、広域公開鍵「ＰＫＥＹ１０」で暗号化された印刷送信用データＤ１０を復号することができないので、印刷をすることもできない。このため、サーバ２０が配信した印刷送信用データＤ１０の印刷が認められるプリンタの地理的範囲を、所定の領域に（この例では図４の２０ｋｍ四方の領域に）制限することができる。
【０１１８】
なお本発明は上記実施形態に限定されずに種々に変形可能である。例えば、上述した実施形態の広域印刷要求処理においては、広域公開鍵で暗号化した印刷送信用データＤ１０を送信したサーバ２０は、各プリンタからの印刷結果情報を待つこととしたが、必ずしもこの印刷結果情報を待つ必要はない。すなわち、印刷送信用データＤ１０を送信したサーバ２０は、その時点で広域印刷要求処理を終了するようにしてもよい。
【０１１９】
また、上述した実施形態においては、プリンタＡ〜Ｄは、サーバ２０から要求があった場合に、広域公開鍵をサーバ２０に送信するようにしたが、サーバ２０からの要求がなくとも、プリンタＡ〜Ｄの方からサーバ２０に広域公開鍵を送信するようにしてもよい。
【０１２０】
さらに、上述した実施形態における公開鍵送信処理においては、サーバ２０の認証情報が、プリンタに登録されている認証情報と一致した場合にのみ、専用公開鍵と広域公開鍵とをサーバ２０に送信することとしたが、認証情報を要求せずに、これら専用公開鍵と広域公開鍵とをサーバ２０に送信するようにしてもよい。
【０１２１】
さらに、上述した実施形態においては、セキュリティを確保すべきデータを送信するデータ送信装置としてサーバ２０を例示し、そのデータを受信するデータ受信装置としてプリンタＡ〜Ｄを例示して、本発明を説明したが、データ送受信システムにおけるデータ送信装置とデータ受信装置の組み合わせは、上記実施形態に限定されるものではない。例えば、データ送受信システムにおけるデータ送信装置が音楽等のコンテンツサーバであり、データ受信装置がコンテンツサーバから送信された音楽等のコンテンツデータの再生装置であってもよい。この場合、コンテンツサーバから送信された送信用データが、再生装置で受信され、再生装置では、この送信用データを広域秘密鍵と専用秘密鍵とで復号し、いずれかの秘密鍵で送信用データが復号できた場合には、送信用データを復号することにより得られたデータを再生し、復号できない場合には、その送信用データに基づく再生をしないこととなる。
【０１２２】
また、上述した実施形態においては、プリンタＡ〜Ｄは位置検出部５４を内蔵していることとしたが、この位置検出部５４は着脱可能な外付けにしてもよい。
【０１２３】
また、上述した実施形態では、プリンタＡ〜Ｄの印刷媒体が印刷用紙である場合を例に説明したが、印刷媒体はこれに限るものではなく、例えば、ＯＨＰシート等の他の印刷媒体であっても本発明を適用することができる。
【０１２４】
また、上述した実施形態では、専用パスフレーズＰＰに、プリンタ位置情報に加えて、プリンタの機器固有情報を用いることとしたが、この機器固有情報を用いないようにしてもよい。この場合、例えば、専用パスフレーズＰＰをプリンタ位置情報のみから構成すればよい。
【０１２５】
さらに、上述の実施形態で説明した各処理については、これら各処理を実行するためのプログラムをフレキシブルディスク、ＣＤ−ＲＯＭ（Ｃｏｍｐａｃｔ Ｄｉｓｃ−Ｒｅａｄ Ｏｎｌｙ Ｍｅｍｏｒｙ）、ＲＯＭ、メモリカード等の記録媒体に記録して、記録媒体の形で頒布することが可能である。この場合、このプログラムが記録された記録媒体をサーバ２０及び／又はプリンタＡ〜Ｄ、３２に読み込ませ、実行させることにより、上述した実施形態を実現することができる。
【０１２６】
また、サーバ２０及び／又はプリンタＡ〜Ｄ、３２は、オペレーティングシステムや別のアプリケーションプログラム等の他のプログラムを備える場合がある。この場合、サーバ２０及び／又はプリンタＡ〜Ｄの備える他のプログラムを活用し、記録媒体にはサーバ２０及び／又はプリンタＡ〜Ｄが備えるプログラムの中から、上述した実施形態と同等の処理を実現するプログラムを呼び出すような命令を記録するようにしてもよい。
【０１２７】
さらに、このようなプログラムは、記録媒体の形ではなく、ネットワークを通じて搬送波として頒布することも可能である。ネットワーク上を搬送波の形で伝送されたプログラムは、サーバ２０及び／又はプリンタＡ〜Ｄに取り込まれて、このプログラムを実行することにより上述した実施形態を実現することができる。
【０１２８】
また、記録媒体にプログラムを記録する際や、ネットワーク上を搬送波として伝送される際に、プログラムの暗号化や圧縮化がなされている場合がある。この場合には、これら記録媒体や搬送波からプログラムを読み込んだサーバ２０及び／又はプリンタＡ〜Ｄは、そのプログラムの復号化や伸張化を行った上で、実行する必要がある。
【０１２９】
【発明の効果】
以上説明したように、本発明によれば、印刷データを受信したプリンタであっても、特定の領域に設けられているプリンタでなければ、その印刷データを印刷できないようにし、印刷データのセキュリティを確保することができる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る印刷システムの構成の一例を示す図。
【図２】本実施形態に係るプリンタのハードウェア構成の一例を示す図。
【図３】本実施形態に係るサーバのハードウェア構成の一例を示す図。
【図４】本実施形態におけるプリンタが配置されている空間を、複数の領域で区切った状態を概念的に説明する図。
【図５】本実施形態に係る専用パスフレーズの構成を説明する図。
【図６】本実施形態に係る広域パスフレーズの構成を説明する図。
【図７】本実施形態に係るサーバが保持する公開鍵テーブルの構成を説明する図。
【図８】専用公開鍵を用いて印刷データを暗号化して印刷送信用データを生成し、専用秘密鍵を用いてこの印刷送信用データを復号する概念を説明する図。
【図９】広域公開鍵を用いて印刷データを暗号化して印刷送信用データを生成し、広域秘密鍵を用いてこの印刷送信用データを復号する概念を説明する図。
【図１０】本実施形態に係るサーバが実行する公開鍵要求処理を説明するフローチャートを示す図。
【図１１】本実施形態に係るプリンタが実行する公開鍵送信処理を説明するフローチャートを示す図（その１）。
【図１２】本実施形態に係るプリンタが実行する公開鍵送信処理を説明するフローチャートを示す図（その２）。
【図１３】本実施形態に係るサーバが実行する専用印刷要求処理を説明するフローチャートを示す図。
【図１４】本実施形態に係るサーバが実行する広域印刷要求処理を説明するフローチャートを示す図。
【図１５】本実施形態に係るプリンタが実行する印刷実行処理を説明するフローチャートを示す図（その１）。
【図１６】本実施形態に係るプリンタが実行する印刷実行処理を説明するフローチャートを示す図（その２）。
【符号の説明】
Ａ〜Ｄ プリンタ
１０ ネットワーク
２０ サーバ
４０ ＣＰＵ
４２ ＲＡＭ
４４ ＲＯＭ
４６ 内部バス
４８、５０ インターフェース
５２ 印刷エンジン
５４ 位置検出部
６０ コンピュータ本体
６２ ディスプレイ
６４ ＣＰＵ
６６ ＲＡＭ
６８ ＲＯＭ
７０ 内部バス
７２、７４、７８ インターフェース
７６ ハードディスク[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a printer, a printing system, and a server, and more particularly, to a printer, a printing system, and a server that can perform wide-area printing that permits printing of print data if the printer is located in a specific area.
[0002]
[Prior art]
2. Description of the Related Art A printing system capable of performing wide area printing by distributing certain print data from a single server to a plurality of printers via a network is known. In such a printing system, a server generates print data and transmits the print data by designating a plurality of printers and transmitting the print data by broadcast communication. I have.
[0003]
In such a wide area printing system, various contents can be distributed as print data to a plurality of printers.
[0004]
[Problems to be solved by the invention]
However, some print data distributed by the server may not be printable by all printers connected to the network, but may be printed only in a specific area. For example, if a company has multiple printers installed on its premises, the printers installed on this premises are allowed to print print data, but printers installed elsewhere are not. In some cases, you may not want to allow printing of print data.
[0005]
Therefore, the present invention has been made in view of the above problems, and even if a printer receives print data, it cannot print the print data unless the printer is provided in a specific area. The purpose is to ensure data security.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a printer according to the present invention includes a printer position information obtaining unit for obtaining printer position information for specifying a place where the printer is installed, and a printer position information obtaining unit. First printer position information obtaining means for obtaining information and using the first printer position information as a first printer position information; and a space in which the printer is located is divided into a plurality of areas of a predetermined size. Public key cryptography is performed using first area specifying means for specifying an area to which the printer belongs based on the position information and using the area as first area information, and a wide area passphrase including at least the first area information. A global public key generating means for generating a global public key, and a global public key transmitting means for transmitting the global public key generated by the global public key generating means. And wherein the Rukoto.
[0007]
In this case, when receiving the print transmission data, the second printer position information obtaining means, which obtains printer position information from the printer position information obtaining means and uses this as second printer position information, A second area specifying unit that specifies an area to which the printer belongs based on the position information and uses the area as second area information;
A wide-area secret key generating means for generating a wide-area secret key by public key cryptography using a wide-area passphrase including at least the second area information; and decrypting the print transmission data using the wide-area secret key If the decoding is successful, the printing based on the printing data obtained by decoding the printing transmission data is executed. If the decoding is not possible, the printing based on the printing transmission data is not executed. And a selective print execution unit.
[0008]
In this case, when the wide area public key generation means generates the wide area public key, even if a wide area private key corresponding to the wide area public key is generated, it may be discarded.
[0009]
Further, the wide area passphrase generated by the wide area public key generation means includes, as the first area information, information on the median value of the area to which the printer belongs, and the wide area passphrase generated by the wide area secret key generation means. The passphrase may also include, as the second area information, information on the median of the area to which the printer belongs.
[0010]
In this case, the global passphrase generated by the global public key generation means further includes information on the width of the area, and the global passphrase generated by the global secret key generation means also includes the width of the area. May be further included.
[0011]
Further, the printer position information is acquired from the printer position information acquisition unit, and the acquired printer position information is used as the third printer position information. A dedicated public key generating means for generating a dedicated public key by public key cryptography, and a dedicated key transmitting means for transmitting the dedicated public key generated by the dedicated public key generating means. Good.
[0012]
In this case, when the print transmission data is received, printer position information is acquired from the printer position information acquisition unit, and the acquired printer position information is used as fourth printer position information. Using a dedicated passphrase including at least position information, a dedicated secret key generating means for generating a dedicated secret key by public key cryptography, and decrypting the print transmission data using the dedicated secret key, and decrypting the data. If the printing is successful, printing based on the printing data obtained by decoding the printing transmission data is executed, but if decoding is not possible, printing based on the printing transmission data is not executed. Means may be provided.
[0013]
Further, when the dedicated public key generation means generates the dedicated public key, even if a dedicated secret key corresponding to the dedicated public key is generated, it may be discarded.
[0014]
The dedicated passphrase generated by the dedicated public key generation unit further includes printer-specific information that is information unique to the printer, and the dedicated passphrase generated by the dedicated secret key generation unit also includes: Printer-specific information that is information specific to the printer may be further included.
[0015]
A server according to the present invention is a printing system including a server and a printer connected to the server, wherein the printer acquires printer position information for specifying a place where the printer is installed. A first printer position information obtaining unit that obtains printer position information from the printer position information obtaining unit and the printer position information obtaining unit and uses the obtained printer position information as first printer position information; A first area specifying means for specifying an area to which the printer belongs based on the first printer position information and using the area as first area information; A wide-area public key generating means for generating a wide-area public key by public key cryptography using a wide-area passphrase including at least area information; Transmitting a wide-area public key generated in the step to the server; and a wide-area public key transmitting unit. The server receives the wide-area public key transmitted from the wide-area public key transmitting unit. Means, and a wide area public key holding means for holding the wide area public key received by the wide area public key receiving means.
[0016]
In this case, the server generates print data, reads out the global public key of a printer belonging to an area where printing of the print data is permitted, from the print data generating unit and the global public key holding unit, and reads a global public key. Means, means for encrypting the print data using the wide area public key read by the wide area public key read means, and generating data for print transmission, the first print transmission data generating means; Transmitting the print transmission data generated by the trust data generation unit to a printer belonging to an area in which printing of the print data is permitted, and a print transmission data transmission unit, wherein the printer transmits the print transmission data. Upon receipt, printer position information is obtained from the printer position information obtaining means and is used as second printer position information. Information obtaining means, a second area specifying means for specifying an area to which the printer belongs based on the second printer position information, and using this as second area information; and a wide area path including at least the second area information. A wide-area secret key generating means for generating a wide-area secret key by public key cryptography using a phrase; and decrypting the print transmission data using the wide-area secret key. A first selection print execution unit that executes printing based on print data obtained by decoding transmission data, but does not execute printing based on the print transmission data when decoding is not possible. You may.
[0017]
In this case, when the wide area public key generation means generates the wide area public key, even if a wide area private key corresponding to the wide area public key is generated, it may be discarded.
[0018]
In this case, the wide area passphrase generated by the wide area public key generation means includes, as the first area information, information on the median of the area to which the printer belongs, and is generated by the wide area secret key generation means. The wide area passphrase may also include, as the second area information, information on the median of the area to which the printer belongs.
[0019]
The global passphrase generated by the global public key generation means further includes information on the width of the area, and the global passphrase generated by the global secret key generation means also includes information on the width of the area. Information may be further included.
[0020]
The printer obtains printer position information from the printer position information obtaining means, and uses the printer position information as third printer position information. A dedicated path including at least the third printer position information is provided. Using a phrase, by public key cryptography, to generate a dedicated public key, a dedicated public key generation means, and transmitting the dedicated public key generated by the dedicated public key generation means to the server, a dedicated open key transmission means, Wherein the server receives the dedicated public key transmitted from the dedicated public key transmitting means, a dedicated public key receiving means, and holds the dedicated public key received by the dedicated public key receiving means, A dedicated public key holding unit may be provided.
[0021]
In this case, the server reads, from the dedicated public key holding unit, the dedicated public key of a printer that permits printing of the print data generated by the print data generating unit, the dedicated public key reading unit, and the wide area public key. A second print transmission data generation unit that encrypts the print data generated by the print data generation unit using the dedicated public key read by the read unit to generate print transmission data; and And a print transmission data transmission unit for transmitting the print transmission data generated by the transmission data generation unit to a printer that permits printing of the print data, wherein the printer receives the print transmission data. Then, printer position information is obtained from the printer position information obtaining means, and is used as fourth printer position information. Using a dedicated passphrase including at least the fourth printer position information to generate a dedicated secret key by public key cryptography, using the dedicated secret key generation means; and The print transmission data is decrypted, and if the decryption is successful, the printing based on the print data obtained by decrypting the print transmission data is executed. If the decryption is not possible, the printing based on the print transmission data is performed. And a second selection print execution unit that does not execute the above.
[0022]
In this case, when the dedicated public key generation means generates the dedicated public key, even if a dedicated secret key corresponding to the dedicated public key is generated, it may be discarded.
[0023]
In this case, the dedicated passphrase generated by the dedicated public key generation unit further includes printer-specific information that is information specific to the printer, and the dedicated passphrase generated by the dedicated secret key generation unit also includes Alternatively, printer specific information that is information specific to the printer may be further included.
[0024]
In the server according to the present invention, a space where a printer connected to the server is located is divided into a plurality of areas of a predetermined size, and if the printer belongs to the same area, the same public key becomes a wide area. A wide-area public key holding unit that holds a public key; a dedicated public key holding unit that holds a dedicated public key that is a different public key for each printer; a print data generating unit that generates print data; In the case of a printer located in the first place, if the print data is a wide area print that permits printing of the print data, the print data is encrypted with a wide area public key of the area to generate print transmission data. In a case where the print data is exclusive print that allows only a specific printer at a certain position to print the print data, the print data is encrypted with a dedicated public key of the printer, and the data is printed. Generating transmission data, a second print transmission data generation means, and transmits the generated the print transmitting data, characterized by comprising a print transmitting data transmitting means.
[0025]
The present invention can be realized as a control method for controlling a printer, a control method for controlling a printing system, or a control method for controlling a server. Furthermore, such a program for controlling the printer, the printing system, and the server and a recording medium on which the program is recorded can be realized.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
In a printing system according to an embodiment of the present invention, a printer connected to a network has a dedicated public key dedicated to itself and a wide-area public key common to printers located in a specific area. Is prepared, and the dedicated public key and the global public key are notified to the server. When transmitting print data that permits printing only to a specific printer, the server encrypts the print data using a dedicated public key dedicated to the printer and transmits the encrypted print data. For example, when transmitting print data that permits printing, the print data is encrypted using the wide area public key of the area and transmitted. Print data encrypted with the wide area public key can be printed by a printer located in a specific area, but cannot be printed by a printer located outside the area. This will be described in more detail below.
[0027]
First, a configuration of a printing system according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a hardware configuration of a printing system according to the present embodiment.
[0028]
As shown in FIG. 1, the printing system according to the present embodiment includes a server 20 connected to a network 10 and printers A to D also connected to the network 10. In the present embodiment, the network 10 is configured by the Internet using TCP / IP (transmission control protocol / internet protocol). However, the form of the network 10 is not limited to the Internet, and may be configured by a LAN such as Ethernet, or a mixture of the Internet and the LAN.
[0029]
The server 20 is composed of, for example, various computers called host computers and server computers. In this embodiment, in particular, the server 20 generates print transmission data by encrypting the print data using a public key (dedicated public key or wide area public key), and transmits the print transmission data via the network 10. And transmits it to any of the printers A to D. The number of servers 20 connected to the network 10 is arbitrary, and may be one or a plurality. Further, the server 20 may be configured by a content server or the like in which print image data is stored as content, and is not limited to a computer, and is configured by, for example, a digital camera that needs to print a captured image. May be.
[0030]
In the present embodiment, the printers A to D are so-called network printers. In the present embodiment, particularly, the printers A to D receive the print transmission data from the server 20, decrypt the print transmission data with a secret key (dedicated secret key or wide area secret key), and Only, printing is performed based on the print data obtained by decoding the print transmission data.
[0031]
In the present embodiment, the printers A to D are directly connected to the network 10, and each of the printers A to D has a unique network address. Therefore, the server 20 can transmit the print transmission data to each of the printers A to D by specifying the network address.
[0032]
However, in FIG. 1, the printers A to D are directly connected to the network 10, but may be connected via a printer server or a computer. The number of printers connected to the network 10 is arbitrary, and may be one or more.
[0033]
FIG. 2 is a block diagram for explaining the internal configuration of the printers A to D. FIG. 2 shows the internal configuration of one printer.
[0034]
As shown in FIG. 2, each of the printers A to D includes a CPU (Central Processing Unit) 40, a RAM (Random Access Memory) 42, and a ROM (Read Only Memory) 44, which are mutually internal buses. 46 are connected. A communication interface 48 is connected to the internal bus 46, and the printers A to D are connected to the network 10 via the communication interface 48. Further, an interface 50 is connected to the internal bus 46, and a print engine 52 is connected to the interface 50.
[0035]
Further, a position detection unit 54 is connected to the internal bus 46. The position detecting section 54 has a function of specifying the positions where the printers A to D are installed. In the present embodiment, for example, it is configured by a GPS (global positioning system), and the latitude, longitude, and altitude of the position where the printers A to D are installed can be specified. It is said that the GPS accuracy at the present time is about ± 10 m in latitude, longitude and altitude.
[0036]
However, the position detection unit 54 is not limited to the configuration using the GPS. For example, when the printers A to D are connected to the network 10 by a wireless LAN, the printers A to D are accommodated. The positions of the printers A to D may be specified based on the wireless base station.
[0037]
Further, for example, the positions of the printers A to D may be specified using a mobile communication technology such as a PHS (Personal Handyphone System). Further, when the GPS and the PHS are used together and the GPS radio wave cannot be normally received indoors, the position may be specified based on the PHS radio wave.
[0038]
FIG. 3 is a block diagram for explaining the internal configuration of the server 20. As shown in FIG. 3, the server 20 according to the present embodiment includes a computer main body 60 and a display 62.
[0039]
The computer main body 60 includes a CPU 64, a RAM 66, and a ROM 68, which are connected to each other via an internal bus 70. Further, a communication interface 72 is connected to the internal bus 70, and the server 20 is connected to the network 10 via the communication interface 72.
[0040]
Further, an interface 74 is connected to the internal bus 70, and a hard disk 76 as a mass storage device is connected to the interface 74. An interface 78 is connected to the internal bus 70, and the above-described display 62 is connected to the internal bus 70 via a cable 80 extending from the interface 78.
[0041]
Next, in the printing system according to the present embodiment, the server 20 and the printers A to D are dedicated printing that permits printing of print data only to a specific printer at a specific position, and are located in a certain area. A process in the case of performing a wide area printing that permits printing of print data in the case of a printer will be schematically described.
[0042]
First, as a premise of the present embodiment, it is assumed that the space in which the printer according to the present embodiment is located is virtually divided into a plurality of areas of a predetermined size, as shown in FIG. Regarding the size of one area, the width W in the X direction (longitude) is 20 km, and the width H in the Y direction (latitude) is also 20 km. Although the Z direction (altitude) is not used in the present embodiment, the Z direction may be used. In the present embodiment, it is assumed that the space where the printer is located is configured such that a plurality of such 20 km square areas are virtually arranged in a mesh.
[0043]
Further, it is assumed that the printers A to D are arranged as shown in FIG. 4 in a space having one side of 20 km square. That is, the printer A, the printer B, and the printer C belong to one area, but the printer D belongs to another area.
[0044]
Each of the printers A to D obtains the printer position information, which is the position information of the printer at that time, from the position detection unit 54, and uses the printer position information to obtain its own dedicated public key and the printer located in the area. A common global public key is generated between
[0045]
Specifically, when generating the dedicated public key, as shown in FIG. 5, the printers A to D use the X-direction position and the Y-direction position of the printer position information and their own device-specific information. To generate a dedicated passphrase PP. In the present embodiment, the dedicated passphrase PP is generated by combining the position in the X direction after the device-specific information and the position in the Y direction after the device-specific information. Then, using this dedicated passphrase PP, a public key (dedicated public key) and a secret key (dedicated private key) are generated by public key cryptography, and this dedicated public key is notified to the server 20. However, the private key is discarded without saving.
[0046]
On the other hand, when generating a wide-area public key, as shown in FIG. 6, the printers A to D determine the center of the area to which the printer A belongs in the X direction from the positions in the X and Y directions of the printer position information. A value Xm and a median Ym in the Y direction are calculated. In the present embodiment, the median value Xm in the X direction and the median value Ym in the Y direction are calculated using the following formulas (1) and (2).
(Equation 1)

(Equation 2)

[0047]
Here, X is the position of the printer in the X direction, Y is the position of the printer in the Y direction, X0 is an amount indicating how much the X axis of the mesh is offset from the origin of the X axis of this space, and Y0 is this space. An amount indicating how much the Y axis of the mesh is offset from the origin of the Y axis, W is the width of one area in the X direction, and H is the width of one area in the Y direction. That is, as shown in FIG. 4, when the origin (0, 0) of the virtual space where the printer is located and the origin of the mesh composed of a plurality of areas are shifted by X0 and Y0. There is also. It is also assumed that the printers A to D have notified the printers of X0, Y0, W and H in advance from the server 20. Alternatively, it is assumed that each user has previously set each printer.
[0048]
Subsequently, the printers A to D use the median value Xm in the X direction, the median value Ym in the Y direction, and information (W, H) for specifying the size of one area, and generate the wide area passphrase WP. Generate. In this embodiment, the median value Ym in the Y direction is connected after the median value Xm in the X direction, the width of the region in the X direction (20 km in this case) is connected behind the median value Ym in the X direction, and the median value in the Y direction is connected behind the median value Ym. A global passphrase WP is generated by combining the widths of the regions (here, 20 km). Then, using this wide-area passphrase WP, a public key (wide-area public key) and a secret key (wide-area private key) are generated by public key cryptography, and this dedicated public key is notified to the server 20. However, the wide area public key is discarded without saving.
[0049]
The method of generating the wide area passphrase WP is not limited to this example. In short, the same global passphrase WP may be used between printers belonging to the same area, and a different global passphrase WP may be used between printers belonging to different areas.
[0050]
The dedicated public key and the global public key notified to the server 20 are stored in the public key table TB10 formed on the hard disk 76 of the server 20. FIG. 7 is a diagram illustrating a configuration of the public key table TB10 according to the present embodiment.
[0051]
As shown in FIG. 7, in the public key table TB10, a wide area public key and a dedicated public key are stored and held for each printer. As can be seen from FIG. 7, the global public keys of the printers A to C are all “PKEY1”, which is common. Because the median value Xm in the X direction and the median value Xm in the Y direction are the same between these printers A to C as shown in FIG. This is because the passphrase WP becomes the same. On the other hand, since the printer D has a different median value Xm in the X direction between these printers A to C, the global passphrase WP used when generating the global public key is also different. Therefore, the wide-area public key of the printer D is different from those of the printers A to C.
[0052]
On the other hand, the dedicated public keys of the printers A to D are different for each of the printers A to D. This is because, as shown in FIG. 5, the dedicated passphrase PP used when generating the dedicated public key is different for each of the printers A to D. In the example of FIG. 7, dedicated public keys “PKEY10”, “PKEY11”, “PKEY12”, and “PKEY13” are stored corresponding to the printers A to D, respectively.
[0053]
By storing the public key in the public key table TB10 of the hard disk 78 in this way, even if the server 20 is turned off and turned on again, the public key obtained before that is directly stored in the hard disk 78. It can be read and used.
[0054]
After the server 20 acquires the dedicated public key and the wide area public key of each of the printers A to D in this manner, for example, printing is performed only to the printer A at the same position as when the dedicated public key “PKEY10” is transmitted. If the user wants to transmit the accepted print data, as shown in FIG. 8, after generating the print data D05, the printer A reads out the private key “PKEY10” of the printer A from the public key table TB10 and reads out the private key “PKEY10”. Is used to encrypt the print data D05 to generate encrypted print data D10. Then, the server 20 transmits the encrypted print data D10 to the printer A via the network 10.
[0055]
If the printer A is at the same position as when the dedicated public key “PKEY10” was generated, the same dedicated secret key will be generated even if the dedicated secret key is generated again by the public key cryptography using the dedicated passphrase PP. . That is, a dedicated secret key capable of decrypting the print transmission data D10 encrypted with the dedicated public key “PKEY10” can be obtained again. Therefore, the printer A can decrypt the encrypted print data D10 with the dedicated secret key, obtain the print data D05, and perform printing based on the print data D05.
[0056]
If the printer A has been moved to another location, the position in the X direction and the position in the Y direction of the dedicated passphrase PP shown in FIG. , A different dedicated secret key is generated even if the dedicated secret key is generated by the public key cryptography using. That is, a dedicated secret key that can decrypt the print transmission data D10 encrypted with the dedicated public key “PKEY10” cannot be obtained. For this reason, the printer A cannot perform printing based on the encrypted print data D10.
[0057]
On the other hand, when the server 20 wants to transmit print data that permits printing only to the printers A to C, for example, as shown in FIG. The global public key “PKEY1” common to the printers A to C is read, and the print data D05 is encrypted using the global public key “PKEY1” to generate encrypted print data D10. Then, the server 20 transmits the encrypted print data D10 to the printers A to C via the network 10.
[0058]
If the printers A to C are in the same area as when the dedicated public key “PKEY1” is generated, the same wide-area secret key is generated even if the wide-area passphrase WP is used to generate the wide-area secret key again. Generated. That is, a wide-area secret key that can decrypt the print transmission data D10 encrypted with the wide-area public key “PKEY1” can be obtained again. Therefore, each of the printers A to C can decrypt the encrypted print data D10 with the wide area secret key, obtain the print data D05, and perform printing based on the print data D05.
[0059]
If, for example, printer A among these three printers has been moved to another area, the median Xm in the X direction and the median Ym in the Y direction in the wide area passphrase WP shown in FIG. At least one of them is different from the one when the wide-area public key “PKEY1” is generated. Therefore, even if the wide-area secret key is generated by the public key cryptography using this wide-area passphrase WP, a different wide-area secret key is used. A key is generated. That is, a wide area private key that can decrypt the print transmission data D10 encrypted with the wide area public key “PKEY1” cannot be obtained. For this reason, the printer A cannot perform printing based on the encrypted print data D10.
[0060]
The above is the processing concept of dedicated printing and wide area printing in the printing system according to the present embodiment. Next, in order to realize such processing, each processing executed by the server 20 and the printers A to D will be described in detail. explain.
[0061]
FIG. 10 is a flowchart illustrating a public key request process executed by the server 20. This public key request processing is realized by the CPU 64 reading and executing a public key request program stored in the ROM 68 or the hard disk 76 of the server. Here, the description will be made on the assumption that the server 20 requests the printer A for the public key.
[0062]
As shown in FIG. 10, in this public key request processing, first, the server 20 connects to the printer A via the network 10 (step S100). In the present embodiment, the server 20 establishes a connection between the server 20 and the printer A by specifying the network address of the printer A.
[0063]
Next, the server 20 transmits the authentication information to the printer A (Step S102). In the present embodiment, a combination of a server ID for specifying a server and a password is used as the authentication information. Therefore, the server 20 transmits the server ID and the password to the printer A.
[0064]
Subsequently, the server 20 receives the authentication result indicating whether the authentication has been accepted from the printer A, and determines whether the authentication has been approved by the printer A based on the authentication result (step S104). ). If the authentication has not been approved (step S104: No), the public key request processing ends.
[0065]
On the other hand, if the authentication is approved (step S104: Yes), the server 20 transmits a public key acquisition request to the printer A (step S106). Then, it is determined whether the dedicated public key of the printer A has been received from the printer A (step S108). If the dedicated public key has not been received from the printer A (step S108: No), the process repeats step S108 and waits.
[0066]
On the other hand, when the dedicated public key is received from the printer A (step S108: Yes), the dedicated public key is stored in the public key table TB10 (see FIG. 7) (step S110).
[0067]
Next, the server 20 determines whether or not the wide-area public key of the printer A has been received from the printer A (step S112). If the wide area public key has not been received from the printer A (step S112: No), the process repeats step S112 and waits.
[0068]
On the other hand, when the wide area public key is received from the printer A (step S112: Yes), the wide area public key is stored in the public key table TB10 (see FIG. 7) (step S114).
[0069]
By storing the acquired dedicated public key and the wide area public key in the public key table TB10, the public key request processing according to the present embodiment ends.
[0070]
Next, a description will be given of a public key transmission process executed by the printers A to D in correspondence with the public key request process of the server 20 with reference to FIGS. FIGS. 11 and 12 are flowcharts illustrating a public key transmission process executed by the printers A to D. This public key transmission processing is realized by the CPU 40 reading and executing a public key transmission program stored in the ROM 44 of the printers A to D. Here, as described above, the description will be made on the assumption that the public key is requested from the server 20 to the printer A.
[0071]
As shown in FIG. 11, first, the printer A establishes a connection with the server 20 (step S120). This corresponds to step S100 on the server 20 side described above. Subsequently, the printer A determines whether authentication information has been received from the server 20 (step S122). If the authentication information has not been received (step S122: No), the process of step S122 is repeated to wait.
[0072]
On the other hand, when the authentication information is received from the server 20 (step S122: Yes), it is determined whether the authentication information matches the authentication information registered in the printer A in advance (step S124). Specifically, as described above, the server ID and the password are transmitted from the server 20 as the authentication information. Therefore, the server ID and the password match the server ID and the password registered in advance in the printer A. Determine whether or not.
[0073]
If the authentication information does not match (step S124: No), the printer A transmits an authentication result indicating that the authentication has not been accepted to the server 20 (step S126), and ends this public key transmission processing. . On the other hand, if the authentications match (step S124: Yes), the printer A transmits an authentication result indicating that the authentication has been accepted to the server 20 (step S128).
[0074]
Next, the printer A determines whether a public key acquisition request has been received from the server 20 (step S130). If the public key acquisition request has not been received (step S130: No), the process of step S130 is repeated to wait.
[0075]
On the other hand, when the public key acquisition request is received from the server 20 (step S130: Yes), the printer A acquires the device unique information of the printer A (step S132). Here, the device-specific information is identification information uniquely assigned to the printer A, and includes, for example, a manufacturing serial number and a MAC address of the printer A.
[0076]
Next, the printer A acquires the printer position information of the printer A at that time from the position detection unit 54 (step S134). As described above, the printer position information is acquired from the position detection unit 54 every time when the printer A is moved to another place, the public key (the exclusive This is to generate a public key and a wide area public key.
[0077]
Next, as shown in FIG. 12, the printer A creates a dedicated passphrase PP using the device unique information and the printer position information (step S136). Although various methods for creating the dedicated passphrase PP are conceivable, in the present embodiment, as described with reference to FIG. 5, the printer position information in the X direction is simply added after the device-specific information. The dedicated passphrase PP is created by connecting the position and the position in the Y direction. Note that the dedicated passphrase PP may include data other than the device-specific information and the printer position information.
[0078]
Next, the printer A generates a dedicated public key and a dedicated secret key by public key cryptography using the created dedicated passphrase PP (step S138). Public key cryptography has the property that if the same passphrase is used, the same is generated even if the public key (dedicated public key) and the secret key (dedicated secret key) are generated again. are doing. Subsequently, the printer A transmits only the dedicated public key among the generated dedicated public key and dedicated private key to the server 20 (step S140). The secret key (dedicated secret key) is destroyed without being stored.
[0079]
Next, the printer A creates a wide-area passphrase WP using the printer position information (step S142). Although various methods of creating the wide area passphrase WP are conceivable, in the present embodiment, as described with reference to FIG. 6, the median value Xm in the X direction and the median value in the Y direction of the area to which the printer A belongs. After the value Ym, the wide passphrase WP is created by combining the width in the X direction and the width in the Y direction of each area. Note that the wide area passphrase WP may include data other than the median as long as it is common among printers belonging to the same area. Further, as long as the common passphrase WP is common among printers belonging to the same area, the wide area passphrase WP may be configured with a value other than the central value.
[0080]
Next, the printer A generates a wide area public key and a wide area private key by public key cryptography using the generated wide area pass phrase WP (step S144). Public key cryptography has the property that if the same passphrase is used, the same is generated even if a public key (wide public key) and a private key (wide public key) are generated again. are doing. Subsequently, the printer A transmits only the wide area public key among the generated wide area public key and wide area private key to the server 20 (step S146). Note that the secret key (wide area secret key) is destroyed without being stored. Thus, the public key transmission processing according to the present embodiment ends.
[0081]
Next, a description will be given of a process performed by the server 20 when transmitting print data to a specific printer at a specific position when the server 20 wants the printer to execute printing.
[0082]
FIG. 13 is a flowchart illustrating a dedicated print request process executed by the server 20. This dedicated print request processing is realized by the CPU 64 reading and executing a dedicated print request program stored in the ROM 68 or the hard disk 76 of the server. Here, the description will be made on the assumption that the server 20 requests printing only to the printer A.
[0083]
As shown in FIG. 17, the server 20 creates print data D05 based on a user's print request (step S150). The print data D05 is data necessary for actually performing printing when the printer A is a normal printer.
[0084]
Next, the server 20 reads out the private key “PKEY10” of the printer A from the public key table TB10 of the hard disk 76 (step S152). Subsequently, the server 20 encrypts the print data D05 using the printer A's dedicated public key "PKEY10" to generate print transmission data D10 (step S154). Note that the print transmission data D10 may include data other than the print data D05.
[0085]
Next, the server 20 transmits the encrypted print transmission data D10 to the printer A (step S156). More specifically, the print transmission data D10 is transmitted to the network 10 by designating the network address of the printer A.
[0086]
Next, the server 20 determines whether print result information has been received from the printer A (step S158). If the print result information has not been received (step S158: No), the process of step S158 is repeated to wait. On the other hand, if the print result information has been received (step S158: Yes), it is determined whether the print result information is a print completion notification (step S160).
[0087]
If the print result information is a print completion notification (step S160: Yes), it means that the printing has been completed normally at the printer A, and the user of the server 20 has completed the printing at the printer A. Is notified (step S162). On the other hand, if the received print result information is not a print completion notification (step S160: No), it is determined whether the print result information is a decipherable notification (step S164).
[0088]
If the print result information is a non-decipherable notification (step S164: Yes), the user is notified that printing was not performed because the print transmission data could not be decrypted by the printer A (step S166). . On the other hand, if the print result information is not the incomprehensible notification (step S164: No), it is considered to be some other error, and the user is notified according to the type of the error (step S168).
[0089]
The dedicated print request processing in the server 20 is completed by the notification of step S162, step S166, and step S168.
[0090]
Next, a description will be given of a process performed by the server 20 when transmitting print data to a printer in a certain area when the server 20 wants the printer to execute the printing.
[0091]
FIG. 14 is a flowchart illustrating a wide area print request process executed by the server 20. The wide area print request processing is realized by the CPU 64 reading and executing a wide area print request program stored in the ROM 68 or the hard disk 76 of the server 20. Here, the description will be made on the assumption that the server 20 performs print distribution to the printers A to C.
[0092]
As shown in FIG. 14, the server 20 creates print data D05 based on a print request from a user (step S200). This print data D05 is data necessary for actually performing printing when the printers A to C are normal printers.
[0093]
Next, the server 20 reads a wide-area public key “PKEY1” common to the printers A to C from the public key table TB10 of the hard disk 76 (Step S202). Specifically, a wide area public key “PKEY1” of one printer (for example, printer A in FIG. 7) in an area where printing of the print data D05 is permitted is read from the public key table TB10. Which printer's global public key is to be read is arbitrary. If the printer is located in one area, the global public key is common, so it is sufficient to read the global public key of any one of the printers. In other words, printers with the same global public key are located in the same area.
[0094]
Subsequently, the server 20 encrypts the print data D05 using the common public key “PKEY1” common to the printers A to C, and generates print transmission data D10 (step S204). Note that the print transmission data D10 may include data other than the print data D05.
[0095]
Next, the server 20 transmits the encrypted print transmission data D10 to all the printers in the area (step S206). In this example, the network addresses of the printers A to C are specified, and the print transmission data D10 is transmitted to the network 10. However, when there is a common broadcast address for the printers A to C, transmission may be performed by broadcast.
[0096]
Next, the server 20 determines whether print result information has been received from any of the printers A to C (step S208). If the print result information has not been received from any printer (step S208: No), the process of step S208 is repeated to wait. On the other hand, if the print result information has been received from any of the printers (step S208: Yes), it is determined whether the print result information is a print completion notification (step S210).
[0097]
If this print result information is a print completion notification (step S210: Yes), it means that the printer has completed printing normally, so that the user of the server 20 can print to the corresponding printer. Is notified (step S212). On the other hand, if the received print result information is not a print completion notification (step S210: No), it is determined whether or not the print result information is a decipherment impossible notification (step S214).
[0098]
If the print result information is a non-decipherable notification (step S214: Yes), the user is notified that the printing was not performed because the corresponding printer could not decode the print transmission data (step S216). ). On the other hand, if the print result information is not the incomprehensible notification (step S214: No), it is considered to be some other error, and the user is notified according to the type of the error (step S218).
[0099]
After the notification in step S212, step S216, and step S218, it is determined whether or not print result information has been received from all the printers that transmitted the print transmission data D10 in step S206 (step S220). If the print result information has not been received from all the printers (step S220: No), that is, if there are still printers that have not received the print result information, the above steps from step S208 are repeated.
[0100]
On the other hand, if the print result information has been received from all the printers (step S220: Yes), the wide area print request processing in the server 20 ends.
[0101]
Next, a print execution process executed by the printers A to D corresponding to the dedicated print request process and the wide area print request process of the server 20 will be described with reference to FIGS. FIGS. 15 and 16 are flowcharts illustrating the print execution processing executed by the printers A to D. The print execution process is realized by the CPU 40 reading and executing a print execution program stored in the ROM 44 of the printers A to D. Here, as described above, the description will be made on the assumption that the server 20 has requested the printer A to perform printing.
[0102]
As shown in FIG. 15, the printer A determines whether the print transmission data D10 has been received from the network 10 (step S270). If no print transmission data D10 has been received (step S270: No), the process of step S270 is repeated to wait.
[0103]
On the other hand, if the print transmission data D10 has been received (step S270: Yes), the printer A acquires its own device-specific information (step S272). Subsequently, the printer A acquires the printer position information of the printer A at that time from the position detection unit 54 (step S274). The reason that the printer position information is acquired from the position detection unit 54 each time is that when the printer is moved to another location, the printer is installed in a location not intended by the user of the server 20. There is a possibility that the printing has been performed or there is a possibility that it is not located in the intended area. In such a case, the printing is not performed by the printer.
[0104]
Next, the printer A creates a dedicated passphrase PP based on the device unique information and the printer position information (step S276). The method of creating the dedicated passphrase PP needs to be the same as the method of step S136 in the above-described public key transmission process. This is because, if the dedicated passphrase PP is different, the print transmission data D10 encrypted with the dedicated public key transmitted to the server cannot be decrypted with the dedicated secret key.
[0105]
Next, the printer A generates a dedicated public key and a dedicated secret key by public key cryptography using the dedicated passphrase PP (step S278). Subsequently, the printer A decrypts the received print transmission data D10 using the generated dedicated secret key, and obtains the print data D05 (step S280).
[0106]
Next, the printer A determines whether the print transmission data D10 has been successfully decrypted using the dedicated secret key (step S282). If the decryption has succeeded (step S282: Yes), the printing that drives the print engine 52 is executed based on the obtained print data D05 (step S284). Specifically, the language interpretation of the print data D05 is performed, and print request data suitable for the print engine 52 is generated. By transmitting the print request data to the print engine 52, the print engine 52 performs printing on a print sheet or the like.
[0107]
At the time when the printing is normally completed, the printer A transmits a print completion notification to the effect that the printing has been normally completed to the server 20 as print result information (step S286). Then, the process returns to step S270.
[0108]
On the other hand, if it is determined in step S282 that the print transmission data D10 has not been decrypted (step S282: No), as shown in FIG. A wide area passphrase WP is created (step S290). The method of creating the wide area passphrase WP needs to be the same as the method of step S142 in the above-described public key transmission process. This is because, if the global passphrase WP is different, the print transmission data D10 encrypted with the global public key transmitted to the server 20 cannot be decrypted with the global private key.
[0109]
Next, the printer A generates a wide-area public key and a wide-area private key by public key cryptography using the wide area passphrase WP (step S292). Subsequently, the printer A decrypts the received print transmission data D10 using the generated wide area secret key, and obtains the print data D05 (step S294).
[0110]
Next, the printer A determines whether the print transmission data D10 has been successfully decrypted using the wide area secret key (step S296). If the decryption has succeeded (step S296: Yes), the printing that drives the print engine 52 is executed based on the obtained print data D05 (step S298). Specifically, the language interpretation of the print data D05 is performed, and print request data suitable for the print engine 52 is generated. By transmitting the print request data to the print engine 52, the print engine 52 performs printing on a print sheet or the like.
[0111]
At the time when the printing is completed normally, the printer A transmits a print completion notification to the effect that the printing has been normally completed to the server 20 as print result information (step S300). Then, the process returns to step S270.
[0112]
On the other hand, if it is determined in step S296 that the print transmission data D10 could not be decrypted using the wide area secret key (step S296: No), a decryption failure notification is transmitted to the server 20 as print result information. (Step S302). Then, the process returns to step S270.
[0113]
As described above, according to the printing system according to the present embodiment, the server 20 limits the printer capable of printing the print transmission data D10 encrypted and transmitted using the dedicated public key based on the printer position information. Therefore, it is possible to prevent printing from being performed by a printer at a position not intended by the user of the server 20. For example, when the printer A is moved to another location, but the network address of the printer A in the network 10 is not changed, the server 20 erroneously transmits the print transmission data D10 to the printer A. However, since the printer A has changed the printer position information, the dedicated passphrase PP created in step S276 is different from that before the movement. Therefore, even if the dedicated secret key generated using this dedicated passphrase PP is used, the print transmission data D10 cannot be decrypted, and the printer A does not perform printing. Therefore, the security of the print data D05 can be enhanced.
[0114]
On the other hand, also on the printers A to D side, a person who normally has no authority to print on the printers A to D sends the print data D05 to these printers A to D, and a large amount of printing Can be avoided. For example, for some reason, even if a third party knows the network address of the printer A and tries to transmit the print transmission data D10 to the printer A, the exclusive public key of the printer A cannot be obtained. If this user encrypts print data D05 with a different dedicated public key to generate print transmission data, or generates print transmission data without encryption, and transmits print transmission data to printer A. Even if this is the case, it is determined that decoding cannot be performed in steps S282 and S296 of the print execution process, so that the printer A cannot execute printing. Therefore, the security of the printers A to D can be enhanced.
[0115]
Further, in the present embodiment, the device-specific information is also included in the dedicated passphrase PP. Therefore, even if a third party knows the positions of the printers A to D for some reason, the printers A to D cannot be used. If the device-specific information is not known, the dedicated passphrase PP used in the printers A to D cannot be specified. For this reason, the possibility that a third party without proper authority executes printing on the printers A to D can be extremely low.
[0116]
Further, according to the printing system according to the present embodiment, the server 20 can limit the range of the printer that can print the print transmission data D10 transmitted to a plurality of printers to a predetermined area. That is, in the example of the present embodiment, the print data D05 is encrypted with the wide area public key “PKEY10” common to these printers A to C so that only the printers A to C within the predetermined area can print. Thus, print transmission data D10 was generated. Therefore, as long as the printers A to C are located in this area, the print transmission data D10 can be decrypted and printed. That is, when the print transmission data D10 is received, in step S290, the same wide-area passphrase WP generated in step S142 is generated, so the same wide-area secret key generated in step S142 is generated. . By using this wide area secret key, the received print transmission data D10 can be decrypted.
[0117]
For example, when the printer A moves to another area, the printer A can receive the print transmission data D10 unless the network address of the printer A has been changed. However, since the printer position information is different from that when the global public key is generated, when the print transmission data D10 is received, in step S290, the same global passphrase WP as the global passphrase WP generated in step S142 is received. Can not get. For this reason, a global secret key different from the global secret key generated in step S144 is generated. As a result, the print transmission data D10 encrypted with the wide-area public key "PKEY10" cannot be decrypted, and thus printing cannot be performed. For this reason, the geographical range of the printer in which printing of the print transmission data D10 distributed by the server 20 is permitted can be limited to a predetermined area (in this example, an area of 20 km square in FIG. 4).
[0118]
Note that the present invention is not limited to the above embodiment, and can be variously modified. For example, in the wide area print request processing of the above-described embodiment, the server 20 that has transmitted the print transmission data D10 encrypted with the wide area public key waits for print result information from each printer. There is no need to wait for result information. That is, the server 20 that has transmitted the print transmission data D10 may end the wide area print request processing at that time.
[0119]
Further, in the above-described embodiment, the printers A to D transmit the wide-area public key to the server 20 when requested by the server 20. Alternatively, a wide-area public key may be transmitted to the server 20 from .about.D.
[0120]
Furthermore, in the public key transmission processing in the above-described embodiment, the dedicated public key and the wide area public key are transmitted to the server 20 only when the authentication information of the server 20 matches the authentication information registered in the printer. However, the dedicated public key and the wide area public key may be transmitted to the server 20 without requesting the authentication information.
[0121]
Further, in the above-described embodiment, the present invention will be described by exemplifying the server 20 as a data transmitting device for transmitting data to be secured and the printers A to D as data receiving devices for receiving the data. However, the combination of the data transmission device and the data reception device in the data transmission / reception system is not limited to the above embodiment. For example, the data transmission device in the data transmission / reception system may be a content server for music or the like, and the data reception device may be a device for reproducing content data such as music transmitted from the content server. In this case, the transmission data transmitted from the content server is received by the playback device, and the playback device decrypts the transmission data with the wide area secret key and the dedicated secret key, and transmits the transmission data with one of the secret keys. Is decoded, the data obtained by decoding the transmission data is reproduced. If decoding is not possible, the reproduction based on the transmission data is not performed.
[0122]
Further, in the above-described embodiment, the printers A to D have the built-in position detecting unit 54, but the position detecting unit 54 may be detachably attached externally.
[0123]
Further, in the above-described embodiment, the case where the print medium of the printers A to D is a print sheet has been described as an example. However, the print medium is not limited to this, and may be another print medium such as an OHP sheet. However, the present invention can be applied to such cases.
[0124]
Further, in the above-described embodiment, the printer-specific information is used for the dedicated passphrase PP in addition to the printer position information. However, the device-specific information may not be used. In this case, for example, the dedicated passphrase PP may be composed only of the printer position information.
[0125]
Further, for each process described in the above-described embodiment, a program for executing each of the processes is recorded on a recording medium such as a flexible disk, a CD-ROM (Compact Disc-Read Only Memory), a ROM, and a memory card. Thus, it can be distributed in the form of a recording medium. In this case, the above-described embodiment can be realized by causing the server 20 and / or the printers A to D and 32 to read and execute the recording medium on which the program is recorded.
[0126]
Further, the server 20 and / or the printers A to D and 32 may include another program such as an operating system or another application program. In this case, the server 20 and / or other programs provided in the printers A to D are utilized, and the recording medium performs processing equivalent to the above-described embodiment from the programs provided in the server 20 and / or the printers A to D. An instruction for calling a program to be realized may be recorded.
[0127]
Further, such a program can be distributed not as a recording medium but as a carrier wave through a network. The program transmitted in the form of a carrier wave on the network is taken into the server 20 and / or the printers A to D, and the above-described embodiment can be realized by executing the program.
[0128]
In addition, when a program is recorded on a recording medium or transmitted as a carrier wave over a network, the program may be encrypted or compressed. In this case, the server 20 and / or the printers A to D that have read the program from the recording medium or the carrier wave need to execute the program after decoding and decompressing the program.
[0129]
【The invention's effect】
As described above, according to the present invention, even if the printer receives print data, the print data cannot be printed unless the printer is provided in a specific area, and security of the print data is improved. Can be secured.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a configuration of a printing system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a hardware configuration of a printer according to the embodiment.
FIG. 3 is a diagram showing an example of a hardware configuration of a server according to the embodiment.
FIG. 4 is a diagram conceptually illustrating a state in which a space in which a printer according to the embodiment is arranged is divided into a plurality of areas.
FIG. 5 is an exemplary view for explaining the configuration of a dedicated passphrase according to the embodiment;
FIG. 6 is an exemplary view for explaining the configuration of a wide-area passphrase according to the embodiment;
FIG. 7 is an exemplary view for explaining the configuration of a public key table held by a server according to the embodiment;
FIG. 8 is a diagram illustrating the concept of encrypting print data using a dedicated public key to generate print transmission data, and decrypting the print transmission data using a dedicated secret key.
FIG. 9 is a view for explaining the concept of encrypting print data using a wide area public key to generate print transmission data, and decrypting the print transmission data using a wide area private key.
FIG. 10 is an exemplary flowchart illustrating a public key request process executed by the server according to the embodiment.
FIG. 11 is a flowchart illustrating a public key transmission process performed by the printer according to the embodiment (part 1).
FIG. 12 is a flowchart illustrating a public key transmission process performed by the printer according to the embodiment (part 2).
FIG. 13 is a view showing a flowchart for explaining dedicated print request processing executed by the server according to the embodiment;
FIG. 14 is a flowchart illustrating a wide area print request process executed by the server according to the embodiment.
FIG. 15 is a diagram (part 1) illustrating a flowchart for describing print execution processing executed by the printer according to the embodiment.
FIG. 16 is a diagram (part 2) illustrating a flowchart for describing print execution processing executed by the printer according to the embodiment.
[Explanation of symbols]
AD printer
10 Network
20 servers
40 CPU
42 RAM
44 ROM
46 Internal bus
48, 50 interface
52 Print Engine
54 Position detector
60 Computer body
62 Display
64 CPU
66 RAM
68 ROM
70 Internal bus
72, 74, 78 interface
76 Hard Disk

Claims (19)

Printer position information obtaining means for obtaining printer position information specifying the place where the printer is installed,
A first printer position information acquiring unit that acquires printer position information from the printer position information acquiring unit and uses the acquired printer position information as first printer position information;
The space where the printer is located is divided into a plurality of areas of a predetermined size, and based on the first printer position information, an area to which the printer belongs is specified, and this is defined as first area information. First region specifying means;
A wide-area public key generating means for generating a wide-area public key by public key cryptography using a wide-area passphrase including at least the first area information;
Transmitting a wide-area public key generated by the wide-area public key generation means, a wide-area public key transmission means,
A printer comprising: A second printer position information acquiring unit that acquires printer position information from the printer position information acquiring unit when receiving the print transmission data, and uses the acquired printer position information as second printer position information;
A second area specifying unit that specifies an area to which the printer belongs based on the second printer position information and uses the area as second area information;
A wide-area secret key generation unit that generates a wide-area secret key by public key cryptography using a wide-area passphrase including at least the second area information;
Using the wide area secret key, the print transmission data is decrypted, and if the decryption is successful, printing based on the print data obtained by decrypting the print transmission data is executed. Does not execute printing based on the print transmission data, a first selected print execution means,
The printer according to claim 1, further comprising: 3. The printer according to claim 2, wherein when the wide area public key generation means generates the wide area public key, even if a wide area private key corresponding to the wide area public key is generated, the key is discarded. The wide area passphrase generated by the wide area public key generation means includes, as the first area information, information on a median value of an area to which the printer belongs,
The wide area passphrase generated by the wide area secret key generation means also includes, as the second area information, information on the median value of the area to which the printer belongs.
The printer according to claim 3, wherein: The global passphrase generated by the global public key generation means further includes information on the width of the area,
The wide-area passphrase generated by the wide-area secret key generation unit also includes information on the width of the area.
The printer according to claim 4, wherein: A third printer position information acquisition unit that acquires printer position information from the printer position information acquisition unit and uses the acquired printer position information as third printer position information;
A dedicated public key generating means for generating a dedicated public key by public key cryptography using a dedicated passphrase including at least the third printer position information;
Transmitting a dedicated public key generated by the dedicated public key generation means, a dedicated open key transmission means,
The printer according to any one of claims 1 to 5, further comprising: A fourth printer position information acquiring unit that acquires printer position information from the printer position information acquiring unit when receiving the print transmission data, and uses the acquired printer position information as fourth printer position information;
A dedicated secret key generation unit that generates a dedicated secret key by public key cryptography using a dedicated passphrase including at least the fourth printer position information;
Using the dedicated secret key, the print transmission data is decrypted, and if decryption is successful, printing based on the print data obtained by decrypting the print transmission data is executed. Does not execute printing based on the print transmission data, a second selected print execution means,
The printer according to claim 6, further comprising: 8. The printer according to claim 7, wherein when the dedicated public key generation means generates the dedicated public key, even if a dedicated private key corresponding to the dedicated public key is generated, the private key is discarded. The dedicated passphrase generated by the dedicated public key generation unit further includes printer-specific information that is information specific to the printer,
The dedicated passphrase generated by the dedicated secret key generation unit further includes printer-specific information that is information specific to the printer.
9. The printer according to claim 8, wherein: A printing system having a server and a printer connected to the server,
The printer is
Printer position information obtaining means for obtaining printer position information specifying the place where the printer is installed,
A first printer position information acquiring unit that acquires printer position information from the printer position information acquiring unit and uses the acquired printer position information as first printer position information;
The space where the printer is located is divided into a plurality of areas of a predetermined size, and based on the first printer position information, an area to which the printer belongs is specified, and this is defined as first area information. First region specifying means;
A wide-area public key generating means for generating a wide-area public key by public key cryptography using a wide-area passphrase including at least the first area information;
Transmitting a wide-area public key generated by the wide-area public key generation means to the server, a wide-area public key transmission means,
With
The server comprises:
Receiving the wide area public key transmitted from the wide area public key transmitting means, a wide area public key receiving means,
Holding the wide area public key received by the wide area public key receiving means, a wide area public key holding means,
A printing system comprising: The server comprises:
Print data generating means for generating print data;
From the global public key holding unit, read the global public key of a printer belonging to an area where printing of the print data is permitted, a global public key reading unit,
A first print transmission data generating unit that encrypts the print data using the wide public key read by the wide public key read unit and generates print transmission data;
Print transmission data transmission means for transmitting the print transmission data generated by the first print transmission data generation means to a printer belonging to an area in which printing of the print data is permitted;
With
The printer is
A second printer position information obtaining unit that obtains printer position information from the printer position information obtaining unit when the print transmission data is received, and uses this as second printer position information;
A second area specifying unit that specifies an area to which the printer belongs based on the second printer position information and uses the area as second area information;
A wide-area secret key generation unit that generates a wide-area secret key by public key cryptography using a wide-area passphrase including at least the second area information;
Using the wide area secret key, the print transmission data is decrypted, and if the decryption is successful, printing based on the print data obtained by decrypting the print transmission data is executed. Does not execute printing based on the print transmission data, a first selected print execution means,
The printing system according to claim 10, further comprising: 12. The printing system according to claim 11, wherein when the wide area public key generation unit generates the wide area public key, even if a wide area private key corresponding to the wide area public key is generated, the key is discarded. . The wide area passphrase generated by the wide area public key generation means includes, as the first area information, information on a median value of an area to which the printer belongs,
The wide area passphrase generated by the wide area secret key generation means also includes, as the second area information, information on the median value of the area to which the printer belongs.
13. The printing system according to claim 12, wherein: The global passphrase generated by the global public key generation means further includes information on the width of the area,
The wide-area passphrase generated by the wide-area secret key generation unit also includes information on the width of the area.
The printing system according to claim 13, wherein: The printer is
A third printer position information acquisition unit that acquires printer position information from the printer position information acquisition unit and uses the acquired printer position information as third printer position information;
A dedicated public key generating means for generating a dedicated public key by public key cryptography using a dedicated passphrase including at least the third printer position information;
Transmitting a dedicated public key generated by the dedicated public key generation means to the server, a dedicated key transmission means,
With
The server comprises:
Receiving the dedicated public key transmitted from the dedicated public key transmitting means, a dedicated public key receiving means,
Holding the dedicated public key received by the dedicated public key receiving means, dedicated public key holding means,
The printing system according to any one of claims 10 to 14, further comprising: The server comprises:
From the dedicated public key holding unit, read the dedicated public key of a printer that permits printing of the print data generated by the print data generation unit, a dedicated public key reading unit,
A second print transmission data generation unit that encrypts the print data generated by the print data generation unit and generates print transmission data using the dedicated public key read by the wide area public key read unit;
A print transmission data transmitting unit that transmits the print transmission data generated by the second print transmission data generation unit to a printer that permits printing of the print data;
With
The printer is
A fourth printer position information obtaining unit that obtains printer position information from the printer position information obtaining unit when receiving the print transmission data, and uses this as fourth printer position information;
A dedicated secret key generation unit that generates a dedicated secret key by public key cryptography using a dedicated passphrase including at least the fourth printer position information;
Using the dedicated secret key, the print transmission data is decrypted, and if decryption is successful, printing based on the print data obtained by decrypting the print transmission data is executed. Does not execute printing based on the print transmission data, a second selected print execution means,
The printing system according to claim 15, comprising: 17. The printing system according to claim 16, wherein, when the dedicated public key generation unit generates the dedicated public key, even if a dedicated private key corresponding to the dedicated public key is generated, it is discarded. . The dedicated passphrase generated by the dedicated public key generation unit further includes printer-specific information that is information specific to the printer,
The dedicated passphrase generated by the dedicated secret key generation unit further includes printer-specific information that is information specific to the printer.
The printing system according to claim 17, wherein: A space where a printer connected to the server is located is divided into a plurality of areas of a predetermined size, and a wide area which holds a wide area public key which is the same public key if the printer belongs to the same area. Public key holding means;
Dedicated public key holding means for holding a dedicated public key that is a different public key for each printer,
Print data generating means for generating print data;
If the printer is located in a certain area, and the printing is the wide area printing that permits the printing of the print data, the print data is encrypted with the wide area public key of the area to generate print transmission data. Transmission data generating means;
In a case where the print data is dedicated print that allows only a specific printer at a certain position to print the print data, the print data is encrypted with a dedicated public key of the printer to generate print transmission data. Transmission data generating means;
Transmitting the generated print transmission data, print transmission data transmission means,
A server comprising:

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