Method and system for performing secure electronic messaging

• US 6,002,769 A
• Filed: 09/04/1997
• Issued: 12/14/1999
• Est. Priority Date: 06/20/1997
• Status: Expired due to Term

• Current Assignee: Qwyit LLC
• Original Assignee: Secure Choice LLC
• Inventors: McGough, Paul
• Primary Examiner(s): Hayes, Gail O.
• Assistant Examiner(s): SONG, HOSUK
• Application Number:
  US08/923,095
• Time in Patent Office: 831 Days
• Field of Search: 380/28, 380/42, 380/45
• US Class Current: 380/28
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/003 for power analysis, e.g. differential power analysis [DPA] or simple power analysis [SPA]
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

A secure electronic messaging system (SEMS) provides absolute system security and user-defined message security for electronic messaging between two public entities. These messages can be of any kind provided the contents are created using a defined master alphabet of 81 characters or less. The SEMS encrypts and decrypts source message data using a series of message keys that are derived from a private, numeric original key known only by both parties sending and receiving messages. The message key suite absolutely secures the original key from discovery. The secure distribution of these original keys will be under the same methods that the public entities would use to discover each other such as opening an account, making a public inquiry for membership, etc. The system is based on the simple mathematics for secure electronic monetary transactions that translates source numbers into encrypted cipher numbers. The SEMS translates message content characters into numbers based on a message key suite dependent distribution of the master alphabet and then uses a series of equations to encrypt the numbers. The formulas return every possible number value, except the input value, and are completely dependent on the message key suite. Because there are no hidden parts, the architecture of the SEMS is completely available to anyone in the public sector. This openness makes attempting message decryption worthless. The only way to break an individual message is to attempt all user-defined message key possibilities, and even if successful, the original key can not be derived or discovered. The only way to get the key is to physically steal it; which is the constant risk entailed in secure messaging. The total openness and absolute security delivered by the SEMS is what is missing in all other available secure messaging schemes, and it is what is required by the public to have complete confidence in electronic messaging and commerce.

Claims

1. A method for encrypting a message comprising the steps of:

a) calculating a numerical value corresponding to each digit of a source key by using said each digit of the source key as an input variable to one of a first plurality of formulae, thereby creating a message key;

b) selecting said one of the first plurality of formulae in step a) based on a corresponding digit of a random key; and

c) distributing an alphabet of characters throughout a predetermined matrix for each individual message based on the message key by;

(i) determining an order fill pattern for the alphabet;

(ii) determining a start position of an alphabet fill in the matrix from two predetermined digits of the message key;

(iii) determining a start position of a blank fill from two additional predetermined digits of the message key;

(iv) determining a blank separation value from two more predetermined digits of the message key;

(v) determining a blank grouping value from two further predetermined digits of the message key;

(vi) designating a plurality of blank positions in the matrix starting at a position in the matrix equal to a modular sum of the start position of the alphabet fill plus the start position of the blank fill, continuing for a number of positions in the matrix equal to the blank grouping value, and then skipping a number of positions in the matrix equal to the blank grouping value; and

(vii) distributing the alphabet in the matrix by starting at the start position of the alphabet fill and filling all positions not designated as blank positions according to the order fill pattern.

2. A method for encrypting a message comprising the steps of:

a) calculating a numerical value corresponding to each digit of a source key by using said each digit of the source key as an input variable to one of a first plurality of formulae, thereby creating a message key;

b) selecting said one of the first plurality of formulae in step a) based on a corresponding digit of a random key;

c) distributing an alphabet of characters throughout a predetermined matrix for each individual message based on the message key;

d) calculating a numerical value corresponding to each digit of the source key by using said each digit of the source key as an input variable to one of a second plurality of formulae, thereby creating the random key; and

e) selecting said one of the second plurality of formulae in step d) based on a second digit of the source key that is cyclically offset from said each digit in step d) in accordance with a random number.

3. The method according to claim 2, wherein the step e) of selecting further comprises the substeps of:

(i) using a digit of the random number corresponding to said each digit of the source key to determine a cyclical positional offset from said each digit of the source key;

(ii) determining said second digit of the source key in step e) by cyclically moving a number of digits from said each digit of the source key in accordance with the cyclical positional offset; and

(iii) selecting another one of said second plurality of formulae based on a third digit of the source key that is offset from said second digit of the source key by a predetermined amount if said one of the second plurality of formulae in step e) returns a value of zero.

16. The method according to claim 2, further comprising the steps of:

f) encrypting each digit of the random number by using said each digit of the random number as an input variable to one of a third plurality of formulae;

g) selecting said one of the third plurality of formulae in accordance with a cyclically corresponding digit of a base source key; and

h) transmitting the encrypted random number as part of the encrypted message.

17. The method according to claim 16, wherein the step g) of selecting further comprises the substeps of:

(i) inserting a random digit in the encrypted random number when said cyclically corresponding digit of the base source key equals zero; and

(ii) using a next digit in the base source key to select said one of the third plurality of formulae when said cyclically corresponding digit of the base source key equals zero.

18. The method according to claim 16, further comprising the steps of:

i) pairing predetermined digits of the original key; and

j) modular summing the paired digits of the original key to obtain the base source key.

4. A method for encrypting a message comprising the steps of:

a) calculating a numerical value corresponding to each digit of a source key by using said each digit of the source key as an input variable to one of a first plurality of formulae, thereby creating a message key;

b) selecting said one of the first plurality of formulae in step a) based on a corresponding digit of a random key;

c) distributing an alphabet of characters throughout a predetermined matrix for each individual message based on the message key;

d) calculating a numerical value corresponding to each character of the message by cyclically using a corresponding digit of the message key as an input variable to one of a second plurality of formulae, thereby creating an encrypted message; and

e) selecting said one of the second plurality of formulae based on a location in the matrix in which said each character in step d) is stored.

8. The method according to claim 4, further comprising the step of:

f) determining a number n by selecting predetermined digits of the source key; and

g) inserting a plurality n of false characters at a beginning of the encrypted message for each message.

9. The method according to claim 4, further comprising the step of:

f) interspersing a plurality of false characters throughout the encrypted message.

10. The method according to claim 9, further comprising the step of:

g) determining a starting position, a separation value and a grouping value of the false characters using predetermined digits of the source key.

11. The method according to claim 4, further comprising the step of:

f) appending an encrypted digital signature to each encrypted message that is completely unique and individual for each message that authenticates both a sender and content of the message as genuine.

12. The method according to claim 11, further comprising the step of:

g) determining a digital signature based on manipulating digits of the encrypted message in accordance with a predetermined algorithm.

13. The method according to claim 12, wherein the predetermined algorithm comprises the steps of:

(i) summing all position values for each integer from zero through nine used in the encrypted message;

(ii) concatenating a resulting sum for each integer in order according to an order in which said each integer first appears in a random number; and

(iii) using a lowest to highest ordering for those integers that do not appear at all in said random number.

14. The method according to claim 12, further comprising the step of:

h) encrypting each digit of the digital signature by cyclically using each digit of the source key as an input variable to one of a third plurality of formulae; and

i) selecting said one of the third plurality of formulae in accordance with a location of said each digit of the digital signature in said matrix.

15. The method according to claim 12, further comprising the step of:

h) encrypting each digit of the digital signature by cyclically using two digits of the source key as input variables to a first one of a third plurality of formulae and a second one of a third plurality of formulae, respectively;

i) selecting said first one of the third plurality of formulae in accordance with a column in the matrix in which said each digit of the digital signature is located; and

j) selecting said second one of the third plurality of formulae in accordance with a row in the matrix in which said each digit of the digital signature is located.

5. A method for encrypting a message comprising the steps of:

a) calculating a numerical value corresponding to each digit of a source key by using said each digit of the source key as an input variable to one of a first plurality of formulae, thereby creating a message key;

b) selecting said one of the first plurality of formulae in step a) based on a corresponding digit of a random key;

c) distributing an alphabet of characters throughout a predetermined matrix for each individual message based on the message key

d) calculating two numerical values corresponding to each character of the message by cyclically using two corresponding digits of the message key as input variables to a first one of a second plurality of formulae and a second one of said second plurality of formulae, respectively, thereby creating an encrypted message;

e) selecting said first one of the second plurality of formulae based on a column in the matrix in which said each character in step d) is stored; and

f) selecting said second one of the second plurality of formulae based on a row in the matrix in which said each character in step d) is stored.

6. A method for encrypting a message comprising the steps of:

a) calculating a numerical value corresponding to each digit of a source key by using said each digit of the source key as an input variable to one of a first plurality of formulae, thereby creating a message key;

b) selecting said one of the first plurality of formulae in step a) based on a corresponding digit of a random key;

c) distributing an alphabet of characters throughout a predetermined matrix for each individual message based on the message key;

d) modular summing pairs of digits of an original key according to a random number assignment of the pairs of digits of the original key to produce said source key, which has a length less than that of the original key.

7. The method according to claim 6, wherein the step d) of modular summing further comprises the substeps of:

(i) pairing a first digit of the original key with a second digit of the original key, wherein the second digit is offset from the first digit by a first cyclical offset amount;

(ii) determining a first cyclical offset amount based on a digit of the random number corresponding in position to a position of the first digit; and

(iii) selecting a next unused digit in the original key if the second digit paired in step (i) has already been paired with another digit of the original key.

19. A secure electronic messaging system comprising the steps of:

a) assigning to two distinct public entities, two identical original symmetric numeric keys of length n where n is an even number and of set length so that 1×

10^n/2 is a substantial and agreed upon number;

b) using a random number to assign and sum the digits of the original key by a formula that produces a source key one half a length of the original key;

c) using a formula to assign and sum the digits of the original key as they appear in order in pairs to produce a base source key that is one half the length of the original key;

d) using a first plurality of formulae and the base source key to encrypt the random number and add a resulting encrypted random number to a message contents;

e) using a first formula to sum a plurality of digits of the source key to generate a random key;

f) using a second plurality of formulae to generate a unique and individual message key from the random key and the source key;

g) distributing up to an 81 character master alphabet into a 9 by 9 segment matrix uniquely for each individual message based on the message key;

h) distributing an offset of a plurality of false characters uniquely for each message based on the source key and adding these to the message contents;

i) encrypting the original message while distributing interspersed false characters by using a third plurality of formulae and based on the message and source keys;

j) using a second formula to create a message signature that is completely unique and individual for each message that authenticates both the sender and the content of the message as genuine;

k) encrypting the message signature by a fourth plurality of formulae and adding it to the message contents; and

l) formatting for open public transmission a resulting total encrypted message including the encrypted random number, the false character offset, the message content with interspersed false characters and the message signature to be plain ASCII text consisting of two strings of numbers separated by a carriage return and line feed.

20. A method for decrypting an encrypted message comprising the steps of:

a) using a message key to uniquely distribute an alphabet into a matrix for the encrypted message;

b) determining a location value of a character in the matrix by using a digit of the message key as an input variable to a first plurality of formulae, and using a corresponding digit of the encrypted message as a return value of the first plurality of formulae, thereby identifying which one of the first plurality of formulae was used to generate the corresponding digit of the encrypted message, wherein a numerical order of said one of the first plurality of formulae represents said location value; and

c) outputting a character in the matrix at said location value determined in said step b), thereby outputting a decrypted message.

21. The method according to claim 20, wherein the step a) of using a message key to uniquely distribute the alphabet comprises the substeps of:

(i) using a predetermined order fill pattern for the alphabet;

(ii) determining a start position of an alphabet fill in the matrix from two predetermined digits of the message key;

(iii) determining a start position of a blank fill from two additional predetermined digits of the message key;

(iv) determining a blank separation value from two more predetermined digits of the message key;

(v) determining a blank grouping value from two further predetermined digits of the message key;

(vi) designating a plurality of blank positions in the matrix starting at a position in the matrix equal to a modular sum of the start position of the alphabet fill plus the start position of the blank fill, continuing for a number of positions in the matrix equal to the blank grouping value, and then skipping a number of positions in the matrix equal to the blank grouping value; and

(vii) distributing the alphabet in the matrix by starting at the start position of the alphabet fill and filling all positions not designated as blank positions according to the order fill pattern.

22. The method according to claim 20, wherein the step b) of determining a location value further comprises the substeps of:

(i) determining a column value of the character in the matrix by using a first digit of the message key as an input variable to a first plurality of formulae, and using a first corresponding digit of the encrypted message as a return value of the first plurality of formulae, thereby identifying which one of the first plurality of formulae was used to generate the first corresponding digit of the encrypted message, wherein a numerical order of said one of the first plurality of formulae represents said column value; and

(ii) determining a row value of the character in the matrix by using a second digit of the message key as an input variable to a first plurality of formulae, and using a second corresponding digit of the encrypted message as a return value of the first plurality of formulae, thereby identifying which one of the first plurality of formulae was used to generate the second corresponding digit of the encrypted message, wherein a numerical order of said one of the first plurality of formulae represents said column value.

23. The method according to claim 20, further comprising the step of:

d) generating the message key from the encrypted message and an original key.

24. The method according to claim 20, further comprising the steps of:

d) calculating a numerical value corresponding to each digit of a source key using said each digit of the source key as an input variable to one of a second plurality of formulae, thereby creating the message key; and

e) selecting said one of the second plurality of formulae in step d) based on a corresponding digit of a random key.

25. The method according to claim 24, further comprising the steps of:

f) calculating a numerical value corresponding to each digit of the source key by using said each digit of the source key as an input variable to one of a third plurality of formulae, thereby creating the random key; and

g) selecting said one of the third plurality of formulae in step f) based on a digit of the source key that is offset from said each digit in step f) in accordance with a random number.

26. The method according to claim 25, further comprising the step of:

h) summing pairs of digits of the original key according to a predetermined assignment of the pairs of digits of the original key to produce a base source key, which has a length less than that of the original key;

i) using each digit of the base source key as an input variable to one of a fourth plurality of formulae;

j) using a corresponding predetermined digit in a predetermined location within the encrypted message as a return value from said fourth plurality of formulae for each digit of the base source key, thereby identifying which one of the fourth plurality of formulae was used to generate said corresponding predetermined digit; and

k) determining each digit of the random number from a formula number corresponding to said one of the fourth plurality of formulae that was used to generate the corresponding predetermined digit.

27. The method according to claim 25, further comprising the step of:

h) generating the source key by summing pairs of digits of the original key based on pair assignments obtained in a predetermined manner from a random number.

28. The method according to claim 24, further comprising the step of:

f) generating each digit of the random key by using each digit of the source key as an input variable to one of a third plurality of formulae; and

g) selecting said one of the third plurality of formulae based a first offset digit of the source key that is offset from said each digit of the source key in accordance with a predetermined digit of the random number.

29. The method according to claim 28, further comprising the step of:

h) selecting another one of said third plurality of formulae based on a second offset digit of the source key that is offset from said first offset digit of the source key by a predetermined amount of digits if said one of the third plurality of formulae in step g) returns a value of zero.

30. The method according to claim 27, further comprising the step of:

i) determining a number n by selecting predetermined digits of the source key; and

j) discarding a plurality n of false characters at a beginning of the encrypted message for each message.

31. The method according to claim 27, further comprising the step of:

f) discarding a plurality of false characters interspersed throughout the encrypted message.

32. The method according to claim 31, further comprising the step of:

g) determining a starting position, a separation value and a grouping value of the plurality of false characters using predetermined digits of the source key.

33. The method according to claim 20, further comprising the step of

d) checking an encrypted digital signature appended to each encrypted message to determine if the message is authentic.

34. The method according to claim 33, further comprising the step of:

e) decrypting each digit of the encrypted digital signature to obtain a decrypted digital signature by the substeps of;

(i) using a corresponding digit of a source key as an input variable to a second plurality of formulae;

(ii) using said each digit of the encrypted digital signature as a return value of the second plurality of formulae, thereby identifying which one of the second plurality of formulae was used to generate said each digit of the encrypted digital signature;

(iii) using a numerical order of said one of the second plurality of formulae identified in step (ii) as a location value in said matrix; and

(iv) outputting a character stored in said location in said matrix.

35. The method according to claim 33, further comprising the step of

e) decrypting the encrypted digital signature by decrypting each pair of digits of the encrypted digital signature according to the substeps of:

(i) using two corresponding digits of a source key as input variables to a second plurality of formulae;

(ii) using a first digit of said each pair of digits of the encrypted digital signature as a first return value of the second plurality of formulae, thereby identifying a first one of the second plurality of formulae that was used to generate said first digit of said each pair of digits of the encrypted digital signature;

(iii) using a numerical order of said first one of the second plurality of formulae identified in step (ii) as a row value in said matrix; and

(iv) using a second digit of said each pair of digits of the encrypted digital signature as a second return value of the second plurality of formulae, thereby identifying a second one of the second plurality of formulae that was used to generate said second digit of said each pair of digits of the encrypted digital signature;

(v) using a numerical order of said second one of the second plurality of formulae identified in step (iii) as a column value in said matrix; and

(vi) outputting a character located at a column and a row of said matrix according to said column and row values, respectively.

36. The method according to claim 34, further comprising the steps of:

f) manipulating digits of the encrypted digital message in accordance with a predetermined algorithm to obtain a recipient generated digital signature; and

g) comparing the recipient generated digital signature with the decrypted digital signature.

37. The method according to claim 36, wherein the predetermined algorithm comprises the steps of:

(i) summing all position values for each integer from zero through nine used in the encrypted message;

(ii) concatenating a resulting sum for each integer in order according to an order in which said each integer first appears in a random number; and

(iii) using a lowest to highest ordering for those integers that do not appear at all in said random number.