PSC-1 Cryptography
Revision 1.1
Monday 1st of November 1999
Simon Cullen
simonpcullen@yahoo.com
Preface
This document is designed to provide a overview of the PSC-1 algorithm. PSC-1 is a public key crypto-
system designed to provide a stronger & faster alternative to the famous RSA algorithm. The PSC-1
algorithm was invented by me and all rights are reserved to me.
If you require anymore information about the PSC-1 algorithm or have any critism, please contact me via
simonpcullen@yahoo.com.
Overview
1976, a revolution in cryptography occurred. Whitfield Diffie, Martin Hellman and Ralph Merkle, developed
what is known as public key cryptography. Public key cryptography is a encryption/decryption method
where two keys are generated, a public key and a private key. Data encrypted with the public key can only
be decrypted using the private key. Public keys do not require secrecy, they can be safely exchanged
through unsecured channels without compromising system integrity. Only disclosure of the private key is a
compromise, and only one person's communications are vulnerable.
However, the Diffie-Hellman-Merkle system did not have any method for users to authenticate a documents
orgin. Ron Rivest, Adi Shamir, and Leonard Adleman developed a public-key system that addressed this
problem. This system is known as RSA.
RSA Encryption/Decryption
Functions
C = M^E mod N
M = C^D mod N
Calculating powers can be very cumbersome, particalurly when the exponent is 128 bits wide or larger. This
problem causes the RSA algorithm to be very slow, about a 1000 times slower then DES. A fast hardware
implentation of RSA with a 512 bit modulus would struggle to reach a throughtput of 64 kilobits per second.
As we enter the new millenium and computer computation speeds become faster, another problem with RSA
becomes apparent, common value detection. Since RSA provide no ability to alter the intial keys, data is
alway encrypted with the same value. Hense x will always equal y in any instance x is encrypted.
With PCS-1 algorithm I have attempted to solve the above main problems found in the RSA system. The
simplest way to understand the PSC-1 algorithm is to break it up into small digestable pieces. Below is the
algorithm it's self. N is defined as the code size, D is the decryption key, DI is the decryption index, E is the
encryption key, EI is the encryption index, M is the message, MI is the message index, C is the cipher
message and CI is the cipher message index.
Key Generation
1. Choose a random number called N. N determines the size of the code space (number of possible values
to be encrypted). Thus if bitwise encryption is desired, N must be > 256. For strong encryption N should be
large - 1024 bits, for instance, is very strong.
2. Choose a random prime number that is < N called E.
3. Compute D such that D * E mod N = 1
