JPH10135943A - Portable information storage medium, verification method and verification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manage with security a key used for verification of a digital signature or the like in a network. SOLUTION: An IC card 10 that contains a public key certificate 4 consisting of a public key 1 and a digital signature 3 of a certificate agency(CA) with respect to the public key 1 and a private key 2, and also a public key 5 of the CA is used for both a sender and a receiver in the case of the public key 1 and the private key 2 used for the verification of the public key encryption system, such as the RSA signature method. The sender sets an IC card 10a acquired from the CA, through an off-line to a network terminal and uses the private key 2 to generate a digital signature and adds the digital signature and the public key certificate 4 to a message and transmits the resulting message to the receiver. The receiver verifies the signature of the received public key certificate 4 of the CA, by using the public key 1 of the CA of the IC card 10b acquired from the CA through an off-line to verify the public key 1 of the sender. The signature of the sender is verified by the verified public key 1 of the sender to verify the message.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for more securely managing keys used for authentication when transmitting information in a network. In particular, the present invention relates to a technique for securely and efficiently managing a secret key and a public key of a public key cryptosystem used for authentication such as a digital signature.

[0002]

2. Description of the Related Art In recent years, networks have become widespread as information transmission means, and in the further development of commercial transactions and the like on networks, techniques that can ensure the validity of information to be transmitted have become extremely important. For example, there is a method of attaching a digital signature as authentication information. FIG. 3 is an explanatory diagram of a digital signature. A digital signature is a type of certificate that a message sender attaches to a message. In addition, it is a conventional seal on paper. The digital signature is usually a cipher text 7 obtained by encrypting a compressed text obtained by compressing a message (original text) 6 using an encryption key of a sender (the original text to be encrypted may be all or a part of the message). .), The original compressed text can be decrypted with the sender's decryption key. In other words, the receiver creates a compressed text from the received message, and decrypts the received digital signature to create another compressed text, and the content of the received message is falsified by matching these two compressed texts. And judge that it is correct. The digital signature also proves that the message was indeed created by the sender. That is, if a paper-based signature is a paper-based one, the sender's seal stamped on the notification sheet on which the message to be transmitted is written, and the validity of the written content and the written content It indicates that it was created by hand. Therefore,
Digital signatures have the functions of both message authentication and user authentication. For a paper-based seal, the digital signature is also an electronic seal.

[0003] By the way, an encryption key and a decryption key are the same key,
That is, in the case of the target encryption, both the keys used by the sender and the recipient need to be secret keys (secret key cryptosystem).
However, when the encryption key and the decryption key are different asymmetric encryption, only one of them can be used as a secret key and the other can be used as a public key for publicizing (public key cryptosystem). As one of such asymmetric ciphers, RSA (Rivest, Sh
amir, Adelman). In general, the RSA encryption system uses an encryption key as a public key and a decryption key as a secret key. However, when the RSA encryption system is used for digital signature, an encryption key is used as a secret key and a decryption key is used as a public key. This is called the RSA signature method. This is because the sender only needs to securely store his or her own key used for encryption as a secret key, and it is safe to publish the decryption key for the secret key as a public key. This is the same as storing your seal on paper and keeping it safe.

[0004] By the way, even on a paper base, a proof that the seal imprint of the stamped seal (official seal) belongs to the sender is a public institution called a seal (registration) certificate having the seal of the official seal. The seal is certified by the documents issued by the company. Therefore, a document with a seal and a seal certificate certifying that the seal is the person's identity are one.
For the first time in a set, the validity of the document is confirmed. Similarly, in the case of a digital signature, in order to use a decryption key as a public key, a trusted authority, that is, a notary authority (C
A: Certification Authority
y) needs a means to prove that the public key is the one of the sender. That is the public key certificate. That is, an electronic seal seal certificate is used for a paper-based seal seal certificate. By the way, a public key certificate issued by a notary public organization also considers the public key as one piece of information, and includes the information (public key) and a digital signature of the notary public organization on the information. Thus, the message that the sender sends to the recipient is now the public key, corresponding to the case where the sender is a notary. The notary institution creates a digital signature of the notary institution with the private key of the notary institution, and the public key that constitutes the public key certificate is the public key of the notary institution, which is paired with the above-mentioned private key of the notary institution. It is used for decryption and authentication. Accordingly, when the sender sends information such as a message to the recipient, the sender, together with the message, the sender's digital signature for the message, a decryption key for authenticating the message from the digital signature, and the sender's own decryption key And a certificate of a notary institution (this certificate includes the decryption key).

[0005]

However, when a public key cryptosystem such as RSA is used for authentication, it is necessary to strictly manage its own private key. Even if stored, there is a risk of unauthorized access by third parties and theft or tampering. The public key used as the decryption key is a public key, so there is no problem of plagiarism. However, falsification can be prevented by keeping a public key certificate of a notary public institution. However, the acquired public key certificate does not function as a certificate if it is illegally accessed and falsified without the knowledge of the custodian, similarly to the private key.
In other words, an incorrect public key certificate will be sent to the recipient, and even if it can be determined that the certificate is improper, a genuine one has not been sent. However, even if the information is transmitted, it cannot be authenticated that the information is legitimate, and the information is not transmitted. This means that even if a public key certificate by a notary public is used, the security of information transmission cannot be ensured unless the public key certificate can be maintained in a genuine state. If this is compared with a paper-based seal certificate, if the seal imprint of the seal to be proved is falsified, the authenticity of the seal seal certificate is lost.

[0006]

Therefore, according to the present invention, in order to solve the above-mentioned problems and achieve the object, at least one pair of a public key and a secret key of a public key cryptosystem used for authentication such as a digital signature is provided. A public key certificate consisting of a public key and a digital signature of a notary authority for the public key, and a private key are used as a portable information storage medium, for example, an I / O with a built-in CPU.
In addition to being stored in the C card, the public key of the notary institution is also used as stored. Both the sender and the receiver hold and manage their respective IC cards,
By setting it in a card reader / writer when needed, there is no danger of unauthorized access by a third party. The sender's IC card includes, for the sender's public key and private key, a public key certificate for the sender, which includes the sender's public key and a digital signature of a notary institution for the public key. Private key and the public key of the notary institution. On the other hand, the receiver's IC card similarly has a receiver's public key and secret key, a receiver's public key certificate consisting of the receiver's public key and a digital signature of a notary public authority on the receiver's public key, and the receiver's public key certificate. The secret key and the public key of the notary are stored.

[0007] The method of authenticating information using the IC card is as follows. First, the sender obtains the IC card for the sender from a notary institution off-line and sends the authentication information such as a digital signature with the sender's private key contained in the IC card when sending the information to the receiver. The authentication information and the public key certificate of the sender contained in the IC card are sent together with the information to be sent. On the receiver side as well, before or after the sender, the same IC card as the sender, that is, a common notary institution, the IC card for the receiver was obtained off-line, prepared, and stored in the IC card of the receiver. The sender's public key included in the sender's public key certificate is authenticated with the public key of a notary public authority, and the sender's public key and authentication information (for example, a digital signature) sent from the sender are authenticated. Authenticate the information.

Further, when a sender sends information to a recipient over a network, a public key and a secret key of a public key cryptosystem are used for authentication information attached to the information. Means that the sender's IC card is set in the sender's own communication computer or a card reader provided in the communication computer used temporarily, and the equipment on the receiver side is the same as the receiver's IC card. It is assumed that the card is set (in the receiver's own communication computer or a card reader provided in the communication computer used temporarily). And the sender
The authentication information is created from the secret key of the sender's IC card, and the authentication information and the public key certificate stored in the sender's IC card are sent to the receiver together with the information. on the other hand,
The recipient authenticates the sender's public key contained in the sender's public key certificate using the public key of a notary institution accommodated in the recipient's IC card, and the authenticated sender's public key And the authentication information (for example, digital signature) to authenticate the information sent from the sender.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In addition, the term “public key” simply refers to the individual public key for the sender or recipient, and the public key of the notary public body is described as “public key of the notary public body” or “public key of the CA”. Distinguish keys. First, FIG. 2 is an explanatory diagram showing that a pair of public key 1 and secret key 2 and a public key 5 of a notary institution are stored in an IC card as an example of the portable information storage medium 10 of the present invention. The public key 1 is stored in the form of a public key certificate 4 together with a signature 3 of a notary authority CA. The private key 2, the public key certificate 4 (including the public key 1 and the like), and the public key 5 of the notary institution, which are stored in the portable information storage medium, are provided with a rewrite prohibition attribute that prohibits the rewrite attribute. Preferably. It is preferable that the rewrite prohibition attribute is provided at least in the private key. However, it is more preferable that the public key certificate 4 and the public key 5 of the notary institution also have the rewrite prohibition attribute to prevent tampering.
The rewrite prohibition attribute can be realized by using a ROM card in which the portable information storage medium stores the key or the like in a read-only memory. However, the rewrite prohibition attribute is provided by an OS (operating system) function of an IC card having a built-in CPU. Can also be set to Further, it is preferable to set an external read prohibition attribute for preventing the contents of the secret key from being read out to the outside or for prohibiting the readout attribute to the outside, for security, in the secret key. In this regard, it is convenient to use an IC card that has a built-in CPU and controls access rights via the CPU. Moreover, the process of encrypting the original text 6 into the cipher text 7 is performed by the IC
It is possible to pass the original text 6 to the IC card 10 and create and output the ciphertext 7 using the secret key 2 inside the IC card 10 instead of taking out the secret key from the card and performing it. Become. In addition, it is preferable to set both the rewrite prohibition attribute and the external read prohibition attribute in the secret key.

[0010] In the portable information storage medium of the present invention, the private key and the public key of the public key cryptosystem to be accommodated may be those used for digital signature for performing message authentication and user authentication, or those used for message authentication. The digital signature includes a secret key and a public key used for the RSA signature method. The message authentication includes a secret key and a public key used in a redundant encryption method or the like. by the way,
In the portable information storage medium, the public key is stored as a public key certificate with a digital signature of a notary institution, and the public key of the notary institution is also stored.
Hand off to the sender and recipient off-line from a notary. Note that the portable information storage medium of the present invention may also store the name of the owner of the housed secret key, an ID number assigned by a notary institution, and the like.

Next, an authentication method and an authentication system performed using the above portable information storage medium will be described. FIG. 4 is an explanatory diagram for explaining the contents of the information to be sent when a sender, Taro, performs a digital signature as authentication information when sending a certain message to a recipient, Jiro. Taro obtains Taro's private key A and Taro's public key certificate A (having Taro's public key A) from a CA (notary authority).
An IC card A containing the public key is obtained. Taro creates a signature from the message to be sent and Taro's private key A in IC card A. Then, the message, the signature, and the public key certificate A are taken out from the IC card A,
Send these three to Jiro. Jiro also has Jiro's private key B (having Jiro's public key B) before or after the message is sent from Taro from CA (notary authority).
Public key certificate B and IC card B containing CA public key
To get.

FIG. 5 is an explanatory diagram of the procedure from the information received by Jiro to the final authentication of Taro's message. First, Jiro confirms that the transmitted public key certificate A is authentic with the public key of the CA contained in the IC card B. For the sake of convenience, the arrow in the figure indicates the confirmation of the seal imprint of the official seal stamped on the seal seal certificate, followed by the confirmation of the seal imprint of the official seal stamped on the seal seal certificate, like the confirmation of the paper-based seal seal certificate. Similar to the procedure, the CA signature is authenticated from the CA public key, and the (Taro's) public key A is authenticated from the CA signature. Considering that a signature is both a message authentication and a user authentication, "CA signature authentication" (user authentication for a notary institution that is the issuer of the public key certificate A) and "Taro's public key" The authentication (message authentication) of “A” is performed simultaneously and in parallel. That is, the confirmation of the authenticity of the transmitted public key certificate A is based on the digital signature authentication method shown in FIG. 3, in which the message is the sender's public key and the sender's signature is the signature of the notary authority. This is the process that has been replaced. Recipient Jiro creates a compressed text from Taro's public key A in the received public key certificate A, and also signs the digital signature of the CA in the received public key certificate A,
Jiro's decryption is performed with the public key of the CA contained in IC card B to create another compressed text, and when these two compressed texts match, Taro's public key received as public key certificate A is obtained. Authenticates that it has not been tampered with and is authentic. Then, Taro's signature is authenticated with the authenticated (Taro's) public key A, and the message is authenticated from the (Taro's) signature. As described above, it is determined that the sent message is reliable and that it is sent from Taro.

Next, FIG. 1 is an explanatory diagram of an authentication system for performing authentication on a network using the portable information storage medium and the authentication method as described above. In this figure, before Taro and Jiro send and receive messages to and from each other, an IC card as a portable information storage medium containing private keys and the public key of the CA is stored in advance by a CA (notary authority). When Taro sends a message to Jiro, a digital signature and a public key certificate are attached and sent, and Jiro uses the CA's public key from Jiro's IC card to authenticate the message. It is an explanation.

In the network authentication system shown in FIG.
It is a local area network based on Ethernet or the like, and the authentication server 21 of the notary institution has a database of public keys (such as Taro and Jiro).
IC card reader / writer 2 for issuing 0a, 10b
2 is provided. If both the application and distribution of the IC card are performed offline, such as by mail, the authentication server is not required to connect to the network. However, if the application for issuing the IC card is performed online and the distribution is performed offline, the authentication server must be connected to the network. Must be connected to Then, Taro's terminal 23a transmits the IC card reader 2 so that the digital signature or the like can be attached to the message and sent to Jiro and the like, and the message from Jiro and the like can be authenticated.
4a, and the IC card reader 24a has an IC card 10 (containing a secret key and a public key of a notary institution) of Taro.
a is set. Also, the terminal 23b on the side of Jiro can authenticate the message from Taro, etc., and attach a digital signature or the like to the message so that the message can be sent to Taro or the like.
A card reader 24b is provided, and the IC card reader 24b contains Jiro's (private key, public key of a notary institution, etc.).
The IC card 10a is set.

First, in the first step, Taro and Jiro each apply for registration of their own public key to the same notary institution. In this figure, as indicated by a broken-line arrow, this procedure is off-line such as mailing, without depending on the network (although it may be online, but in the case of this figure). The key is R
A key used for the SA signature method (a secret key and a public key).
Upon receiving the application, the notary institution generates a pair of keys and registers the public key in the public key database. By registering, the notary institution can guarantee the validity of Taro and Jiro's public keys, and can prevent duplicate issuance. Only the public key side needs to be registered. In addition, as a notary institution, for example, a company, a local government in a prefectural level, a country, and the like can play a role according to the purpose. The application for registration of a public key is also an application for obtaining a public key of a notary public institution.

The next step is to provide Taro and Jiro with the private key, the public key, a public key certificate having the notary authority's digital signature for the public key, and the public key of the notary authority, respectively, from the notary authority. The IC card is sent off-line such as by mail. In this process, the respective certificates for the public keys of Taro and Jiro and the public key of the notary public are also sent to Taro and Jiro in the respective IC cards. Therefore, the application for registration of the public key is also an application for a request for a public key by a notary institution. Jiro who is the recipient of the message, at least when receiving the first message, after receiving the message (after the fact), applies to the notary institution for registration of Jiro's own public key (application for the public key request of the notary institution) May be performed).

Taro then sends Jiro a message with Taro's digital signature along with Taro's public key certificate over the network. Taro is an IC card reader 24
Set your IC card 10a in a. The method of creating the digital signature is as described above, and is created by extracting the secret key or encrypting it inside the IC card. In addition, in order to prevent misuse when the IC card itself is stolen, the owner's password may be set for use of the contained private key and reading of the public key certificate.

On the other hand, the Jiro receiving the message, in order to authenticate the authenticity of the public key certificate, in order to authenticate the digital signature of the notary institution in the certificate, The public key is Jiro's IC card 10b
Is housed together with Jiro's public key and private key,
Use the public key of the notary (not related to Taro). As described above, Jiro may obtain his or her IC card 10b from a notary institution after Taro has sent the message (after the fact) or before (before the fact).
Then, Jiro sets his / her IC card 10b obtained from the notary institution into the card reader 24b, and uses the public key of the notary institution contained in the IC card 10b to generate the public key certificate sent from Taro. It authenticates the signature of the notary institution and authenticates Taro's public key. Next, Jiro authenticates Taro's message with the authenticated Taro's public key.

As described above, according to the present invention, every time a message is sent from Taro, a sender, when a public key of a CA is obtained by Jiro, a recipient, a certificate is sent to a notary institution online.
Requests A's public key, and the Notary Authority gives Jiro online C
There is no need for complicated procedures such as sending the public key of A. In other words, if the public key of the CA is sent from the notary public to Jiro online, even if the public key of the CA is published, in order to prevent tampering by a third party during online transmission, the public key of the CA is required. In order to prove that the certificate is the one of the notary institution, security measures such as sending it as a public key certificate for the CA's public key are required. This public key certificate is issued by a higher notary authority higher than the notary authority, and the CA of the lower notary authority
Is a certificate for the public key of the CA, which is composed of the public key of the CA and the digital signature of the higher-level notary authority on the public key of the CA. The upper and lower ranks of the notary institution are, for example, local governments for companies and countries for local governments.

Conversely, when a message is sent from Jiro to Taro, Jiro uses Jiro's secret key stored in his IC card 10b as in the case of sending from Taro to Jiro.
Taro uses a public key certificate for Jiro's public key, and Taro uses the public key of a notary institution housed in his IC card 10a.

Finally, according to the present invention, an electronic seal stamp is imprinted as a digital signature on a message transmitted by the sender Taro, and transmission data including the message is transmitted to Jiro.
An example until the recipient Jiro stamps (authenticates) the electronic seal stamp and authenticates the message is shown in the explanatory diagram of FIG. In the figure, the sealer (Taro) 's IC card includes Taro's private key, Taro's private key, Taro's electronic seal certificate issued by CA, and CA's public key, CA.
Public key. In Taro's electronic seal certificate, Taro's public key, which is Taro's public key (that is, Taro's electronic seal), a CA digital signature (seal of the electronic seal) for the public key, Taro's name and Taro , Etc. are included. Then, Taro encrypts the digest obtained by compressing the message to be sent by the hash function with the public key cryptosystem using Taro's private key, which is Taro's private key, and obtains a digital signature ( Taro's electronic seal stamp). The digest compressed by the hash function is data that cannot be restored to the original data. Then, as the transmission data sent from Taro to Jiro, the digital signature of Taro and the digital seal certificate of Taro's sealer issued by CA are sent together with the message to be sealed. On the other hand, Jiro's private key, Jiro's private key, Jiro's electronic seal certificate issued by CA, and the disclosure of CA, CA's public key, are also present in the IC card of Jiro, the recipient and sealer. The key is included. Jiro's electronic seal certificate also contains Jiro's public key (ie, Jiro's electronic seal), which is Jiro's public key.
A CA digital signature (seal of an electronic seal stamp) for the public key, the name of Jiro, a number assigned to Jiro, and the like are included. Then, Jiro compresses the public key, which is Taro's haplic key, in Taro's electronic seal certificate in the received transmission data with a hash function to create a digest. On the other hand, the digital signature of the CA in the electronic seal certificate was decrypted with the public key cryptosystem using the public key that is the haplic key of the CA in Jiro's IC card, and the result was compared with the digest. Then, the public key that is Taro's haplic key in the electronic seal certificate is authenticated. Then, using the public key that is the authenticated Taro's public key, the digest is created by decrypting Taro's digital signature in the transmission data using public key cryptography,
On the other hand, a message in the transmission data is compressed by a hash function to generate a digest, and if these two digests are compared and matched, the message is authenticated, and a series of processes is completed.

[0022]

According to the present invention, it is possible to securely manage each private key and public key used for authentication, the certificate of the public key by a notary authority, and the public key of the notary authority. In the portable information storage medium accommodating these, the secret key, and the public key certificate and the public key of the notary institution have the rewriting prohibited attribute, so that the key can be managed more safely. Further, by encrypting the secret key inside the medium as an external read prohibition attribute, it is possible to more securely manage the secret key that is not externally disclosed. Also, since the keys and the like are stored in the portable information storage medium, it is not necessary to store these keys and the like in the magnetic disk of the own network terminal or the like, and the terminal is used by another person and stored on the magnetic disk. There is no danger of unauthorized keys being stolen or tampered with. The portable information storage medium may be set in the card reader of the terminal only when necessary, and may be managed by the user afterwards. Therefore,
If this portable information storage medium is set in other network terminals, information can be transmitted safely. Also,
In the conventional case where the key is stored in a magnetic disk and used,
In order to prevent theft or tampering by shortening the state of being housed in the magnetic disk in time, it was desirable to use a notary institution to obtain the key every time the key is needed. However, according to the present invention, the key can be safely managed in the portable information storage medium, so that the sender does not need to inquire the notary institution every time, and the notary institution first stores the portable information only once. Once the media has been handed over, the key management on the notary institution can be more efficient. Also, the public key of the notary institution is stored in the portable information storage medium together with their own public key and private key.
Whenever a public key of a notary public is required, there is no need for troublesome procedures such as requesting and obtaining it from the notary public online, and requiring security measures. Therefore, it is possible to authenticate the digital signature of the notary public in the public key certificate sent from the sender off-line, that is, authenticate the public key certificate off-line and authenticate information such as the sender's message. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an authentication system and an authentication method using a portable information storage medium of the present invention.

FIG. 2 is an explanatory diagram of an example of information and functions of a portable information storage medium of the present invention.

FIG. 3 is an explanatory diagram of a digital signature.

FIG. 4 is an explanatory diagram of information transmission contents according to the present invention.

FIG. 5 is an explanatory diagram of an authentication procedure on the receiver side according to the present invention.

FIG. 6 is an explanatory diagram from a seal of a digital signature (electronic seal stamp) to a seal (authentication) as an example of the present invention.

[Explanation of symbols]

1 Public Key 2 Private Key 3 Digital Signature of Notary Authority (CA) 4 Public Key Certificate 5 Public Key of Notary Authority (CA) 6 Original Text (Message etc.) 7 Cryptographic Text (Digital Signature etc.) 10, 10a, 10b Portable Information storage medium (IC card, etc.) 21 Authentication server 22 Card reader / writer 23a, 23b Terminal 24a, 24b Card reader

Claims (9)

[Claims] At least one pair of a public key and a secret key used for authentication of a public key cryptosystem are accommodated as a public key certificate including a public key and a digital signature of a notary public authority for the public key, and a private key, A portable information storage medium that also contains the public key of a notary institution. 2. The portable information storage medium according to claim 1, wherein the stored private key, public key certificate, and public key of the notary public have a rewrite inhibition attribute. 3. The housed secret key has an external reading prohibition attribute, and encrypts an original input from the outside in the medium using the secret key, and outputs a ciphertext. Portable information storage medium. 4. The portable information storage medium according to claim 1, wherein the portable information storage medium is an IC card having a CPU and a memory.
A portable information storage medium according to the item. 5. The portable information according to claim 1, wherein the stored at least one pair of the public key and the secret key are a decryption key and an encryption key used for a digital signature according to the RSA signature method. Storage medium. 6. A public key and a public key of a public key cryptosystem used as authentication information of information when a sender sends information to a receiver on a network, wherein the sender uses a public key and a public key for the sender. By acquiring the portable information storage medium according to any one of claims 1 to 4 from the notary public organization for the private key and the public key of the notary public organization, the public key of the sender and the notary public organization for the public key are obtained. Prepare a public key certificate consisting of a digital signature, a private key of the sender, and a public key of a notary institution, and the sender sends the public key certificate to the recipient together with the authentication information created with the private key. The recipient also obtains the portable information storage medium according to any one of claims 1 to 4 from the notary public organization for the public key and private key of the recipient and the public key of the notary public organization. Public key and the public key A public key certificate consisting of a digital signature of a notary institution, a private key of the recipient, and a public key of the notary institution are prepared, and the recipient receives the certificate of the notary institution stored in the portable information storage medium of the recipient. First, using the public key and the digital signature of the notary authority of the public key certificate sent from the sender, the public key of the sender of the public key certificate is authenticated, and then the authenticated sender An authentication method using a portable information storage medium, which authenticates information sent using a public key of the user and authentication information sent from a sender. 7. The authentication method using a portable information storage medium according to claim 6, wherein the authentication information is a digital signature by an RSA signature method. 8. When a sender sends information to a recipient,
In an authentication system of a network system, wherein a public key and a secret key of a public key cryptosystem are used for authentication information attached to the information, a terminal of a sender and a terminal of a recipient are respectively a public key and a secret key of a sender and a recipient. 5. The public key of a notary authority, comprising: a public key certificate comprising a public key and a digital signature of the notary authority on the public key; a private key; and a public key of the notary authority. Respectively, wherein the sender uses the sender's portable information storage medium and uses the sender's private key stored in the portable information storage medium to perform authentication. Sending the information and a public key certificate for the sender's public key contained in the portable information storage medium, wherein the recipient uses the recipient's portable information storage medium And the public key of the notary agencies housed in the storage medium,
Using the digital signature of a notary institution possessed by the public key certificate sent from the sender, the sender's public key possessed by the public key certificate is first authenticated, and then the authenticated sender's public key and An authentication system using a portable information storage medium, which authenticates information sent using authentication information sent from a sender. 9. The authentication information according to claim 8, wherein the authentication information is a digital signature.
An authentication system using the portable information storage medium described in the above.