Cryptographically secure pseudo random number generator

A method of generating a cryptographically secure random number, comprising the steps of:

• receiving a random number output from a random number generator having a valid output set consisting of M−1 random numbers, and an invalid output set including one invalid output value;
• receiving said invalid output value;
• encrypting said random number using an encryption function to provide an encrypted random number;
• encrypting said invalid output value using said encryption function to generate an encrypted invalid output value;
• adding, in modulo M, said invalid output value to said encrypted random number to determine a sum;
• and
• subtracting, in modulo M, said encrypted invalid output value from said sum to determine a cryptographically secure random number.

A computer readable medium containing program instructions for generating a cryptographically secure random number, said program instructions including instructions for performing the steps comprising:

• generating a random number using a random number generator having a valid output set consisting of M−1 random numbers, and an invalid output set including one invalid output value;
• encrypting said random number via an encryption function to provide an encrypted random number;
• encrypting said invalid output value via said encryption function to generate an encrypted invalid output value;
• adding, in modulo M, said invalid output value to said encrypted random number to determine a sum;
• and
• subtracting, in modulo M, said encrypted invalid output value from said sum.