WO2002003606A1

WO2002003606A1 - A method and system for secure transmission of data

Info

Publication number: WO2002003606A1
Application number: PCT/US2001/021329
Authority: WO
Inventors: Richard Virga; Jack Bittner
Original assignee: Kryptofax Lp.
Priority date: 2000-07-05
Filing date: 2001-07-05
Publication date: 2002-01-10
Also published as: AU2001271855A1; JP2004502966A; EP1307996A1; CN1452824A

Abstract

The present invention provides a method and system for the secure transmission and reception of data over a communication channel. In one embodiment (FIG 11) plaintext data is first encrypted into ciphertext (1130), and ciphertext is then scanned into a bitmap (1140). The bitmap is then encrypted (1150) and then transmitted to a destination location (1155), where it is received (1162) and decrypted into original bitmap (1165-1175). The decrypted bitmap is then scanned for ciphertext, which is subsequently decrypted to original plaintext data (1185-1185). In another embodiment, unencrypted plaintext data is canned into a bitmap, and this bitmap is then encrypted and transmitted (FIG 12, 1205-1290).

Description

A METHOD AND SYSTEM FOR THE SECURE TRANSMISSION OF DATA

CROSS REFERENCES TO ISSUED PATENTS

This application is related to U.S. patent 5,321,749 ("Encryption Device") and U.S. patent 5,398,283 ("Encryption Device" ) . We incorporate into this application, he entire disclosure of U.S. patent 5,321,749 ("Virga 1") and U.S. patent 5, 398, 283 (^λVirga 2") just as if the written specification and drawings were expressly set forth in this application.

FIELD OF THE INVENTION

The present invention relates to the field of information technology and networks. In particular, the present invention pertains to a method and system for the secure transmission of data .

BACKGROUND INFORMATION

This invention relates to a method and system for the secure transmission of data over a communication channel. The invention utilizes a bitmap encryption step in a multi-step encryption process. Many encryption and decryption systems are known, including optical devices and methods . In many of these systems, the "key" to the encryption and decryption lies in a screen or lens; to decrypt a document or message encrypted with a particular screen or lens requires the use of the same or a corresponding screen or lens to that used to encrypt the document or message. Other cryptographic systems operate only on textual information and cannot preserve visible, non-textual information present in a document, such as pictures, symbols, type fonts, or handwriting characteristics . Other systems relating to the encryption of television images are known, but they do not lend themselves to the creation of paper documents that can be handled and sent via facsimile, email or Internet transmission.

Generally, incorporating a bitmap encryption significantly increases the security of the encryption. Standard encryption schemes or even multi-layer standard encryption schemes are vulnerable to cracking by running an iterative process on a CPU. By utilizing a multi-step encryption process involving at least one bitmap encryption step, a potential cracker is forced to utilize an Optical Character Recognition Program which requires significantly greater CPU bandwidth in order to attempt to crack the code.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method and system for the secure transmission and reception of data over a communication channel. The present invention utilizes a multi-step encryption method that, in one or more of the passes, converts the data into a bitmap using the system described in U.S. Pat. Nos . 5,321,749 ("Virga 1") and 5,398,283 ("Virga 2") incorporated as noted above. The bitmap that is generated is then encrypted. The encrypted bitmap is again encrypted and transmitted to a destination location. Alternatively, in one or more of the passes, the data is first encrypted and the encrypted data is converted into a bitmap using the system described in U.S. Pat. Nos. 5,321,749 ("Virga 1") and 5,398,283 ("Virga 2"). The bitmap is then encrypted. The encrypted bitmap is then transmitted to a destination location. At the destination location the encrypted bitmap is received and is then decrypted.

In the first of the foregoing configurations the decrypted bitmap will produce an encrypted bitmap, which is then decrypted to produce a copy of the original data. In the second of the foregoing configurations the decrypted bitmap will produce encrypted data, which is then decrypted to produce a copy of the original data. Any number and order of such configurations and passes can be utilized.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a typical combination document including both textual and non-textual information.

FIG. 2 is a block diagram of a combined encryption/decryption unit .

FIG. 3 is a schematic illustration of a combined encryption/decryption unit. FIG. 4 is a schematic illustration of a typical first page of encrypted outpu .

FIG. 5 is an example of a document with polygons that cannot be optimally identified until the entire page is scanned.

FIGS. 6A-6C are examples of the scanning of a document. FIG. 7 is a schematic example of a page for which polygonal compression of the scanned bitmap is appropriate.

FIG. 8 is an example of a printed encrypted image (PEI) .

FIG. 9 is an example of the reading of the encrypted image symbols into a grid. FIG. 10 is a flow chart illustrating the steps of the method of performing the encryption of a bitmap.

FIG. 11a is a flow chart illustrating the steps of a method for encrypting and transmitting data according to one embodiment of the present invention. FIG. lib is a flowchart illustrating the steps of a method for receiving and decrypting encrypted data according to one embodiment of the present invention.

FIG. 12a is a flow chart illustrating the steps of a method for encrypting and transmitting data according to another embodiment of the present invention.

FIG. 12b is a flowchart illustrating the steps of a method for receiving and decrypting encrypted data according to another embodiment of the present invention.

DETAILED DESCRIPTION

FIGS. 1-10 relate to a method and device to perform bitmap compression (see e.g., Virga 1 and Virga 2) . FIG. 1 represents an exemplary "combination document" 1 which includes both textual and non-textual information, such as pictures. This sample shows different sizes of print 2a 2b, 2c, a picture 3, a chart 4, and a signature 5. Of course, other combinations are possible; indeed the entire document could be hand written. Combination document 1 is not well- suited to standard text encryption methods, because such methods cannot be used to encrypt visual devices such as the picture 3, the chart 4, or the signature 5. Additionally, the presence of non textual features and different size print make it difficult for OCR (optical character recognition) scanners to process the textual content of the document. However, this type of document may be scanned and converted into a bitmap through known methods .

Turning to FIG. 2, a combined encryption/decryption unit is shown. Scanner 6 is of a conventional type known in the art. This device converts the pattern of light and dark on document 1 into a sequence of bits (i.e., a bitmap) representing light and dark pixels on the document by a scanning process. Typically, the bits would simply represent light pixels as a 0 and dark pixels as a 1, or vice versa. By representing each pixel by more than one bit, however, it is possible to represent various shades of gray in half-tone images or even different colors that may be present in the image, as further explained below. The sequence of bits generated is fed into the processor 7.

The processor 7 in this embodiment comprises a microprocessor 8, RAM 9, and ROM 10 wherein ROM 10 controls the operation of microprocessor 8 and includes a program comprising the encryption and decryption algorithms. Display 11 may be an LCD display such as that found on portable personal computers, or it may be a somewhat smaller LCD display, such as the type found on the electronic organizers that are commonplace today. Other types of displays could also be used, although LCD displays are preferred because they are flat and require little power. The processor 7 provides prompting messages through display 11 and controls the operation of the scanner 6 and printer 13. Responses to these prompts are entered by the user on alphanumeric keyboard 12. The printer 13 is connected to processor 7 to print encrypted or decrypted documents, as appropriate.

The encryption of half-tone images and color images requires a scanner capable of scanning and representing such images. For example, if the original image is an industry- standard 256-level gray scale image, a particular scanned pixel could be represented by a number from 0 to 255, representing the lightness or darkness of the pixel, i.e., the gray level or half-tone code. Thus, instead of a one-bit representation of each pixel, in this representation, each pixel has an eight-bit representation. These bits can be encrypted as well, except that they appear eight times larger than a one-bit representation (in the case of a 0 to 255 half tone code) to the encryption algorithm and require eight times the amount of storage per page of document. A similar process can be used for RGB color scanners, where 8-bit representations of red, green, and blue values would yield full 24-bit color representations of documents . The documents could be subject to various types of compression, but it is expected that the encrypted documents will be much larger than documents scanned with a one-bit representation per pixel. Half-tone and color encrypted documents can be printed with an ordinary black-and-white printer, e.g., by printing single bits encoded as black-and white symbols as described below. A symbol indicating "halftone" or "color" should proceed each group of symbols representing the encrypted input pixel, and each group of symbols should either be printed twice, or once with a checksum, to ensure correct interpretation of the encrypted codes and to properly synchronize the decryption algorithm to produce the decrypted output pixels . To properly reproduce encrypted half tone or color images, a half-tone or color printer is required. Assuming that the user intends to encrypt the document (100a of FIG. 10) being scanned, he or she will enter the response appropriate to the encryption operation. (Step 100 of FIG. 10) Processor 7 receives this input from keyboard 12 and further processes the bit-map (100j of FIG. 10) received from the scanner in accordance with the instructions received from the user. Additional prompting may be sent to the display 11 to request information to be entered from the keyboard 12. This information may include non-encrypted information to be printed on every page of output, such as the originator and the intended recipient of the message, the date, and the page number. The processor 7 may generate its own page numbers and a date to be placed on each page of the document. Printing sequential page numbers on each page of the encrypted document is desirable, since, should an encrypted document consist of several pages, there is likely to be no otherwise obvious way of knowing the order in which they should be decrypted should these pages become uncollated.

The encrypted bitmap representation (104b in FIG. 10) is then sent to the printer 13 for printing, along with any printed comments entered by the user through the keyboard 12 and any dates or page numbering or other standard markings that may be entered automatically by the processor 7. A dialog typical of one that might take place between a user wishing to encrypt a document and the device is shown in Table I. (Pressing the "enter" key is shown as [enter] , and the end" key as [end] . )

TABLE I

It is possible to store the entire scanned bitmap of a page prior to processing. This requires, for example, for 2- level (black-and-white) processing, 4.7 megabits of RAM memory, assuming the typical facsimile resolution of 200 dots per inch and a maximum page size of 8.5 by 14 inches (8.5 x 14 x 200 x 200 = 4,760,000 bits) . A real time method can and most preferably will be used as scanning is being performed. By applying the criteria for compression (polygons of all black or all white, for instance) , a mixture of encoded raw bits from the original and polygon codes can be built up in RAM. After the coded structure of the page is completed, printing is performed.

An illustration of how the encryption/decryption unit may look to the user after it is built is shown in FIG. 3. The encryption/decryption unit is housed in a box 14. Documents to be encrypted or decrypted are placed into a hopper 15 from which they are received and sent one page at a time through the scanner inside the box 14. The printer, which is also inside box 14, receives papers from a cassette 16. After pages received from hopper 15 are scanned, they are placed in a bin 17 from which they may be removed. The printed output of the unit is placed in a tray 18. An LCD display 19 is placed at a position convenient for the operator. Display 19 is preferably a multi-line display, but it need only be able to display sufficient information to prompt the user and to provide feedback to the user for information entered from alphanumeric keyboard 20. Keyboard 20 is the means by which the operator of the device communicates with the processor, which is also housed inside the box 14. External power may be supplied to the encryption/decryption unit, or an internal battery pack may be provided for emergencies or portable operation.

No connection with a telephone line is required, because the encryption/decryption engine produces a printed output that may be scanned and e-mailed, faxed, photocopied, bent, and folded (even stapled, under certain conditions to be described later in this Application) in the same manner as any other paper document may be. As pages are fed for encryption, the encryption/decryption unit prints (step 106 of FIG. 10) one or more pages for each page of the original. An illustration of a typical first page of encrypted output is shown in FIG. 4. The output illustrated here shows automatically generated clear (i.e., unencrypted) text 61 generated for the convenience of the recipient, user-entered clear text 60, and the encrypted portion of the document represented by coded symbols 62. A top-of-page code 63 and a bottom-of-page code 64, each containing an entire line of symbols, is also shown. (The bottom of the last page will have a slightly different code so that the end of the encrypted document may be recognized. )

To get the best compression result, the entire page should be scanned and the result held in a buffer in RAM prior to encryption. For example, in FIG. 5, wavy lines 90 are used to schematically represent printing or writing. In FIG. 5, the empty parts of the page 21 and 22 cannot be optimally identified until the whole page is read into the RAM buffer. At that time, however, they could be recognized and coded as unfilled polygons. The encryption (step 104 of FIG. 10) is performed on each page scanned. When the user is prompted for a password as in Table 1, the password is used as a seed for the encryption algorithm. Usually, this means that the password is a seed for a random number generator, although it will be immediately apparent to one skilled in the art that there are numerous encryption algorithms that may be used. It is only necessary that documents encrypted by the encryption algorithm be decrypted by the corresponding decryption algorithm. For encryption that depends upon a random number generator, decryption is dependent upon the same key (104a of FIG. 10) being used in the identical processor. This method of encryption provides security at least as good as that obtained through the use of first class mail or express courier services. For non-compressed processing using this type of encryption, each scan line is processed one bit at a time. This bit is xor-ed with the next sequential zero or one from the fixed sequence seeded random number generator. The result provides the output bit (zero or one) . If more than 20 bits in the scan line or contiguous polygonal area are the same value, it is preferable that binary count or polygon shape and position code be created, including checksum data. The generated count, including the checksum, can then be encrypted and encapsulated with a vertical bar ( | ) enclosing it, and printed on the output page, This is a simple but effective method for compressing contiguous binary data such as the bitmap of a scanned document .

Since 1976, when the Public Key approach to encryption was proposed, exact methods of encryption and their relative effectiveness have been hotly debated. This invention does not require the use of any particular encryption system, although the random number sequence described above is believed to be more than adequate for normal use. Other methods of encryption could be substituted, with greater or lesser security resulting. Moreover, encryption 104a and decryption 110a keys may be but need not be the same, depending upon the method of encryption used. Alternatively, other suitable compression methods could be used, such methods being well-known to those skilled in the art. Nevertheless, the invention does not depend upon the use of compression or the use of any particular encryption and decryption algorithms .

An example of the scanning of a document is shown in FIGS. 6A to 6C. For clarity, a portion 71 of the original document 23 is enlarged in FIG. 6B at 24. The corresponding scanned light and dark pixels are shown at 25 (in FIG. 6C) , each dark pixel being represented in this example as a "1" in the generated bit pattern, and each light pixel being represented as "0." The bit addresses shown at 26 are limited to the sample area for the purposes of this explanation; the generalization to an entire scanned document will be evident from the example. The generated bit pattern is the "picture bitmap" in Table II below.

A password is used to encrypt the scanned bitmap. The binary representation of this password as, for example, an ASCII code may be used as the seed to a repeatable pseudorandom bit generator such as that shown on pages 29-31 of

"Seminumerical Algorithms, " second edition, which is volume 2 of "The Art of Computer Programming" by Donald E. Knuth, published by Addison. Wesley Publishing Company of Reading, Mass. Table II represents the encryption of the picture bitmap in FIG. 6 using a pseudo-random repeatable bit stream:

TABLE II

Picture bitmap 0 0 1 0 0 0 1 0 0 0 1 0 1 1 1

0

Encrypted (XORed) 1 0 0 1 0 0 0 0 0 1 0 1 1 0 0 bitmap 0

The printed encrypted image (PEI) corresponding to this example is illustrated in FIG. 8. As explained more fully below, a symbol alphabet consisting of very simple shapes is used to print the PEI. Alignment markers including beginning- of-line markers 80a, 80b, 80c, and 80d and end-of-line markers 81a, 81b, 81c, and 81d are included. (These markers are shown to enclose only the encrypted portion 71 of the document 23 (referring to FIG. 6) , an obvious simplification made for this example because of the large size of both the encrypted and unencrypted bitmaps. Each page of encrypted output would also have a top-of-page and bottom-of-page marker, not shown in this example.) The various delimiting markers serve to delimit the space in which encrypted symbols appear. Spurious marks, including holes left by staples, appearing outside of these delimiters, are ignored during decryption.

Symbols 82a, 82b, 82c, 82d, and 82e, representing the five "1" bits of the encrypted bitmap are shown placed in an implied grid 83. (The implied grid, delimited by dashed lines 83, is not actually printed on the PEI.) The PEI may then be scanned and e-mailed, faxed, copied, and delivered to the recipient. The PEI is scanned, and, using the alignment markers, the symbols representing the encrypted bitmap are recognized and placed into a corresponding array 84 in FIG. 9. (Darkened blocks 85a, 85b, 85c, 85d, and 85e are the grid elements corresponding to symbols 82a, 82b, 82c, 82d, and 82e, respectively.) The array is then read sequentially and decrypted by the same sequence used to encrypt the original pixels, the sequence being generated by a random bit generator seeded by the password. This decryption is shown in Table III. The decrypted pixels are then placed on the page in a proper grid, which generates the original document 23, or in this example, the portion 71 of the document 23, since it will be seen that the de-crypted pixels in Table III are identical in value and sequence to those of portion 71. Of course, an adjustment in positioning the pixels will be required for decrypting an entire picture, inasmuch as in the preferred case, there will be fewer symbols representing the en-crypted bits than there are pixels in the original picture, unlike this simple example.

TABLE III

Other encryption algorithms can be used, and with public key systems of the sort mentioned above, it is not even required that the passwords used to decrypt and encrypt the document be the same. The example described above does not include compression, (step 102 of FIG. 10) which is preferably applied to a scanned bitmap prior to encryption. Standard compression algorithms operating on a contiguous stream of bits could be used. For example, a fixed length data block preceded by a code indicating "uncompressed" could be used to represent uncompressed data. If the code for "uncompressed" is 01 and the fixed length data block is 32 bits long, a data block with prefix for a particular portion of a scanned bitmap might look l ike this :

(un) compression bitmap data code

01 00000000000000001001001011000101

If a fixed-maximum length compression code is applied, representing between 16 and 496 consecutive zeros or ones (for example) , the above data block could be compressed. Assuming that the compression code is 10 followed by a 0 or a 1 (indicating that the code represents consecutive zeros or ones, respectively) followed by the length of the consecutive string of zeros or ones, up to a maximum of 496, with the length divided by 16, the first 16 bits of the uncompressed bitmap could be represented as follows:

compression repeated repeat count (in code bit binary) divided by 16

10 0 00001

Obviously, the greater the number of consecutive zeros or ones, the greater the compression of the bitmap. In this example, it is clear that repeat counts greater than 496 can be represented simply by additional blocks of compressed or uncompressed data, as required. Polygonal compression can also be used. FIG. 7 shows an example in which there is little opportunity for continuous bit compression, but an appreciable opportunity for compression using polygonal compression. Wavy lines 91 represent text or handwriting, with a substantial white area left at 28. All white area 28 provides the opportunity for polygonal compression. For this method to work, the whole page is scanned into RAM.

Then, polygonal areas of all white or black, for example, are recognized and a code is generated stating where on the page the polygon is to be placed. The code would state the X,Y coordinates of each vertex of the polygon. Polygon codes would be transmitted at the beginning of each page image. The uncompressed or sequentially linearly compressed data would be coded to fill in around the polygons.

After the processor scans the original page and determines the content of the encrypted bitmap, the output page is printed. To ensure a reliable and efficient recognition and decoding of an encrypted document sent by facsimile transmission, and allowing for the ever-present line noise encountered over voice grade telephone lines, it is desirable to print (or skip) four pixel positions for each pixel in the original scan line. This means that a binary "one" is printed as four dots on the encrypted version of the document. In addition, two dots are preferably used as a space between each of the dots, and two lines are used between each scan line. In accordance with this scheme, the encrypted sequence 101 is printed as a two-by-two square (the first 1), followed by a two-by-two space, followed by another two-by-two space (the 0) , followed by a two-by-two space, followed by a two-by-two square (the second 1) . At the end of each printed line, two lines are skipped. To allow the original scan lines to be decrypted, (step 110 of FIG. 10) the end of each original scan line is preferably marked by a double dash (--) in the printout .

The expansion and grouping of pixels described 25 here together with the compression described above means that the end of each original scan line could occur anywhere on a printed output line. It is also preferable that the beginning and ending of each line of encoded printout be marked by vertical bars, that contiguous polygon codes be printed twice, with checksum information, and that additional coding mark the top and bottom of each page, and the start and finish of the document. Although this format is believed preferable for the printed encrypted output, other formats are also possible. One particularly simple modification would be to make the size of the printed squares larger for facsimile transmission if required to combat telephone line noise.

The encrypted document is preferably a deliberately "widely spaced" document. Even with this arrangement of the pixels, however, some may be lost during scanning and decryption due to printing and scanning anomalies in the fax machine and line noise. Since the result is a printed bitmap of the original document, however, some data loss is tolerable and will not result in noticeable loss of user information. Because of the prefer-red wide spacing, encrypted documents will often be larger than the original. If there is a lot of contiguous white or black space in the original, however, the simple compression method described above will reduce the size of the encrypted output. Decryption of the document is essentially one of character recognition. Because of the preferred method of printing the encrypted output, the problem of decryption is essentially one of pattern recognition of a limited alphabet of geometric shapes, i.e., vertical and horizontal lines, dots (or squares), and spaces. As each scan line is read, (step 108 of FIG. 10) the decryption engine determines, from the spaces between the " | " characters, the relative spacing of the characters on the page. To provideorientation, a "start of page code" may be provided. The preferred code is an entire line of dashes, i.e., "-", with orientation bars, i.e., " | ", at either end.

Decryption of the document is dependent upon entering the correct seed. If the bitmap (108b of FIG. 10) is xor-ed with the random number generator, entering an incorrect seed will generate a random pattern of black and white pixels . As multiple scan lines are processed, a compressed bitmap (110b of FIG. 10) for each output page is built up by the microcomputer's memory. As each page is completed, it is decompressed (step 112 of FIG. 10) and a reproduction of the original, unencrypted document is printed. A buffer large enough to store two pages is preferred, with one buffer being used to store a scanned image and the other buffer being used to store the page to be printed (step 114 of FIG. 10) .

It is possible to add the invention to facsimile systems that are built into or added to personal computers (PCs) . Documents can be created within PC applications. These items are then processed by a facsimile processing system including software and hardware imbedded in the PC. Using this embodiment, a personal computer, with its keyboard and display, would replace processor 7, keyboard 12, and display 11 in FIG. 2. The personal computer's scanner and printer would perform the functions of scanner 6 and printer 13, respectively. On the receiving end, the received document would be read by a companion software program in the receiving PC. The decrypted document could then be viewed by the same PC facsimile software that views standard incoming facsimiles. In addition, the invention can be imbedded in standard facsimile machines. It would then be possible to send an encrypted version of the document directly from one machine to another, bypassing the step of printing the encrypted version of the document. At the receiving end, either the encoded document can be printed or a message can be displayed, requesting the recipient to come to the facsimile machine and enter the document password, so that the document can be printed.

Other modifications can be made without departing from the spirit of the invention. For example, the display unit 11 is not limited to an LCD display; a CRT (cathode 10 display tube) display could be used, for example. The keyboard 12 may be of any of various types, preferably small enough to be integral with the unit, although a detachable keyboard could be used. Any of the various technologies currently used for keyboards such as those found on pocket calculators would be suitable, for example. Further, it is possible to completely computerize the system. In such a system, in which a document is created in a computer (e.g., by a word processor), it may never be printed, but instead could be encrypted in the computer, sent as an image (e.g., by the computer's built-in fax) to another computer, decoded, and displayed on a CRT or other suitable display. Another possibility is to output the encrypted image to a diskette or ROM card and then insert it into a decrypter to view it without printing it.

It is also possible to provide processor 7 with multiple encryption and/or decryption algorithms, e.g., different pseudo-random sequence generators that generate different repeatable patterns from the same seed, to generate different levels of security, for example . These could be selected by the user by entering an appropriate response on keyboard 12 to a prompt on display 11. Information as to which encryption algorithm has been used to encrypt a document could be displayed as part of the automatically produced unecrypted text 61, or it could be encoded in any of several places in the encrypted portion of the document, such as by varying the top- of-page code 63, or by embedding an algorithm identifier within the coded symbols 62.

FIG. 11a is a flowchart depicting the steps of a transmission/encryption process according to one embodiment of the present invention. The transmission process is initiated in step 1105. In step 1110 it is determined whether the data is encoded in alphanumeric form. If not, in step 1120, the data is converted to alphanumeric format using known methods. In step 1130, the data is encrypted using any encryption method. In step 1140, the encrypted data is converted to a bitmap using known methods (i.e., this is the inverse of performing an OCR step) . In step 1150, the bitmap is encrypted utilizing the bitmap encryption methods discussed herein. In step 1155, the encrypted bitmap is transmitted to a receiver. The process ends in step 1190.

FIG. lib is a flowchart depicting the steps of a reception/decryption process according to one embodiment of the present invention. In step 1162 the process is initiated. In step 1163, an encrypted bitmap is received. In step 1165, the encrypted bitmap is decrypted, e.g., using the bitmap encryption process described herein. In step 1170, the decrypted bitmap is converted to alphanumeric data (e.g., using an OCR process) . In step 1175, the alphanumeric data is decrypted using the inverse process used to decrypt the data in step 1130. In step 1180, it is determined whether the original data contained non-alphanumeric information. If so (^''yes' branch of step 1180) , the alphanumeric data is converted to non-alphanumeric format in step 1185. The process ends in step 1190.

FIG. 12a is a flowchart depicting the steps of a transmission/encryption process according to another embodiment of the present invention. The transmission process is initiated in step 1205. In step 1210 it is determined whether the data is encoded in alphanumeric form. If it is, in step 1220, the alphanumeric data is converted to a bitmap using known methods. In step 1230, if the data is non-alphanumeric the bitmap is encrypted using any encryption method, creating Encrypted Bitmap A. In step 1240, Encrypted Bitmap A is further encrypted, using any encryption method, yielding Encrypted Bitmap B. In step 1250 Encrypted Bitmap B is transmitted. The process ends in step 1290.

FIG. 12b is a flowchart depicting the steps of a reception/decryption process according to another embodiment of the present invention. In step 1262 the process is initiated.

In step 1263, an encrypted bitmap is received. In step 1265, the Encrypted Bitmap B is decrypted, yielding Encrypted Bitmap A. In step 1275 Encrypted Bitmap A is decrypted yielding a decrypted bitmap. In step 1280, if the original data was alphanumeric, the decrypted bitmap from step 1275 is converted to its original alphanumeric form using conventional OCR methods per step 1285. If, in step 1280 the original data was not alphanumeric, the decrypted bitmap from step 1275 is the final output. The process ends in step 1290.

Other implementations are within the scope of the following claims .

Claims

What Is Claimed Is:

1. A method for the secure transfer of data to a destination location, the method comprising the steps of: (a) encrypting alphanumeric data if alphanumeric data is first presented; (b) converting non-alphanumeric data to alphanumeric data and encrypting, if non-alphanumeric data is first presented; (c) converting the first encrypted data to a bitmap; (d) encrypting the bitmap to produce an encrypted bitmap; (e) electronically transmitting the encrypted bitmap to the destination location; (f) receiving the encrypted bitmap; (g) decrypting the encrypted bitmap to produce a second bitmap; (h) converting the second bitmap into a second encrypted alphanumeric data using e.g. OCR; and (i) decrypting the second encrypted alphanumeric data to produce final decrypted data if alphanumeric data was first presented, or; (j) converting alphanumeric data to non-alphanumeric form if non-alphanumeric data was first presented.

2. The method according to claim 1, wherein the encryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

3. The method according to claim 1, wherein the data is coded to represent alphanumeric information using a coding scheme.

4. The method according to claim 3, wherein the coding scheme is Radix-64.

5. The method according to claim 1, wherein the step of converting the second bitmap data into a second encrypted data further includes the step of performing optical character recognition on the second bitmap.

6. The method according to claim 1, wherein step (a) further includes the steps of: generating a second data from the data that is coded to represent alphanumeric information; and encrypting the second data to produce a first encrypted data.

7. The method according to claim 6, further including the steps of converting the second data to a third data that is coded to represent non-alphanumeric information.

8. A method for encrypting and transmitting data, comprising the following steps :

(a) encrypting alphanumeric data if alphanumeric data is first presented; (b) converting non-alphanumeric data to alphanumeric data and encrypting, if non-alphanumeric data is first presented; (c) converting the first encrypted data to a bitmap; (d) encrypting the bitmap to produce an encrypted bitmap; (e) electronically transmitting the encrypted bitmap to the destination location;

9. The method according to claim 8, wherein the encryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

10. The method according to claim 8, wherein the data is coded to represent alphanumeric information using a coding scheme.

11. The method according to claim 10, wherein the coding scheme is Radix-64.

12. The method according to claim 8, wherein step (a) further includes the steps of: generating a second data from the data that is coded to represent alphanumeric information; and encrypting the second data to produce a first encrypted data.

13. A method for decrypting an encrypted bitmap, comprising the following steps: (a) receiving encrypted bitmap; (b) decrypting the encrypted bitmap to produce a second bitmap; (c) converting the second bitmap into a second encrypted alphanumeric data using e.g OCR; and (d) decrypting the second encrypted alphanumeric data to produce final decrypted data if alphanumeric data was first presented, or; (e) converting alphanumeric data to non-alphanumeric form if non-alphanumeric data was first presented.

14. The method according to claim 13, wherein the decryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

15. The method according to claim 13, wherein the data is coded to represent alphanumeric information using a coding scheme.

16. The method according to claim 15, wherein the coding scheme is Radix-64.

17. The method according to claim 13, wherein the step of converting the bitmap into encrypted data further includes the step of performing optical character recognition on the bitmap .

18. The method according to claim 13, further including the step of converting the data to a second data that is coded to represent non-alphanumeric information.

19. A device for encrypting a document, comprising: an optical scanner for scanning the document; a processor coupled to the optical scanner, wherein the processor is adapted to: performing optical character recognition to produce a first data; encrypting the data using an encryption method to produce encrypted data; converting the encrypted data into a bitmap; encrypting the bitmap to produce an encrypted bitmap.

20. A device for decrypting a document, comprising: an optical scanner for scanning the document to produce a bitmap; a processor coupled to the optical scanner, wherein the processor is adapted to: decrypting the bitmap to produce a second bitmap; converting the second bitmap into encrypted data; and decrypting the encrypted data to produce a data using a decryption method.

21. A method for the secure transfer of data to a destination location, comprising the following steps: (a) converting alphanumeric data to a bitmap and then encrypting, if alphanumeric data is first presented; (b) encrypting non-alphanumeric data into a first encrypted bitmap, if non-alphanumeric data is first presented; (c) encrypting the first encrypted bitmap to produce a second encrypted bitmap; (d) electronically transmitting the second encrypted bitmap to the destination location; (e) receiving the second encrypted bitmap; (f) decrypting the second encrypted bitmap to produce an encrypted bitmap; (g) decrypting the encrypted bitmap in (g) , above, into an unencrypted bitmap; (h) converting the unencrypted bitmap into alphanumeric data if alphanumeric data was first presented, using e.g. OCR.

22. The method according to claim 21, wherein the encryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

23. The method according to claim 21, further including the steps of converting the second encrypted bitmap to any number of encrypted bitmaps .

24. A method for encrypting and transmitting data, comprising the following steps: (a) converting alphanumeric data to a bitmap and then encrypting, if alphanumeric data is first presented; (b) encrypting non-alphanumeric data if non-alphanumeric data is first presented; (c) encrypting the first encrypted bitmap to produce a second encrypted bitmap; (d) electronically transmitting the second encrypted bitmap to the destination location.

25. The method according to claim 24, wherein the encryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

26. A method for decrypting a second encrypted bitmap, comprising the following steps: (a) receiving the second encrypted bitmap; (b) decrypting the second encrypted bitmap to produce an encrypted bitmap; (c) decrypting the encrypted bitmap in (g) , above, into an unencrypted bitmap; (d) converting the unencrypted bitmap into alphanumeric data if alphanumeric data was first presented, using e.g. OCR.

27. The method according to claim 26, wherein the decryption method is PGP ("Pretty Good Privacy"), or any other encryption technology.

28. A method for the secure transfer of a data to a destination location, comprising the following steps: (a) encrypting the data using an encryption method to produce a first encrypted version of the data; (b) converting the first encrypted version of the data into a bitmap; (c) encrypting the bitmap to produce an encrypted bitmap; (d) electronically transmitting the encrypted bitmap to the destination location; (e) decrypting the encrypted bitmap to produce a second bitmap; (f) converting the second bitmap into a second encrypted version; and (g) decrypting the second encrypted version to produce a second version of the data using a decryption method.

29. A method for providing secure transmission of data comprising the following steps: (a) encrypting the data using an encryption method to produce a first encrypted version of the data; (b) converting the first encrypted version of the data into a bitmap; (c) electronically transmitting the encrypted bitmap to a destination location.

30. A method of extracting data comprising: (a) receiving an encrypted bitmap; (b) decrypting the encrypted bitmap to produce a second bitmap; (C) converting the second bitmap into a second encrypted version of the data; and (d) decrypting the second encrypted version of the data to produce a second version of the data using a decryption method.