US 2002/0159588 A1Published application

Cryptography with unconditional security for the internet, commercial intranets, and data storage

OwnerJason R. Kauffman, Robert E. Kauffmaninventors

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Abstract

In a pseudorandom coding cipher system and method, a sender generates a pseudorandom shift key using a pseudo-random number generator (PRNG) with seed and/or multiplier numbers from a one-time pad. A plaintext message is converted into a numerical synonym string, wherein the first number of the string is shifted with the shift key. The shift value is then passed through a one-way function to place the shift value in the range of numerical synonyms representative of the plaintext alphabet. This process is repeated until the entire numerical string has been shifted with a respective shift key and passed through the one-way function to produce a cryptogram. To decrypt, the reverse operation is performed to recover the plaintext message. Communications between the sender and a receiver is preferably performed according to a double-key lock box scenario employing double use of the above encryption and decryption methods making one-time pad distribution unnecessary.

Claims20

Dependent claims

A cipher system for encrypting a plaintext message of alphanumerical characters, generated by a source and transmitted between a sender and a receiver, comprising:

a set of nonnegative numerical synonyms for the alphanumerical characters;
a sender processing unit adapted to receive the plaintext message of alphanumerical characters from the source and to convert each alphanumerical character of the plaintext message into a respective numerical synonym of said set of nonnegative numerical synonyms to form a numerical message string;
a pseudorandom number generator adapted to generate pseudorandom numbers, said processing unit being adapted to use said pseudorandom numbers to generate pseudorandom shift keys;
a one-time pad containing a plurality of multipliers and seed numbers accessible to said pseudorandom number generator to generate said pseudorandom numbers, each multiplier and seed number being accessible only once;
a shift cipher adapted to add to each said numerical synonym of said numerical message string a respective one of said pseudorandom shift keys to generate a shifted numerical message string;
and
a one-way function adapted to perform modular subtraction on each numerical value of said shifted numerical message string to generate a ciphertext string having numerical values in said set of nonnegative numerical synonyms.

4 more elements

A method for using a cipher system to transmit a plaintext message of alphanumerical characters, generated by a source, between a sender and a receiver, comprising:

receiving the plaintext message of alphanumerical characters by a sender processing unit;
converting each character of the plaintext message to a related numerical synonym;
providing a seed and/or multiplier number from a one-time pad;
generating pseudorandom numbers with a pseudo-random number generator using said seed and/or multiplier number, each said seed and/or multiplier number being only accessible once from said one-time pad by said pseudo-random number generator;
generating a shift key from said pseudorandom numbers;
shifting a first numerical synonym of said plaintext message with said shift key to generate a shifted numerical value;
passing said shift numerical value through a one-way function adapted to perform modular subtraction on said shifted numerical value to generate ciphertext having a numerical values in said set of nonnegative numerical synonyms;
reseeding said pseudo-random number generator with said pseudorandom numbers to generate new pseudorandom numbers;
and
repeating until every said numerical synonym of said plaintext message has been shifted, passed through said one-way function to form a cryptogram.

7 more elements

Dependencies are inferred from the claim text.