Triple-DES Stream Cipher Using the ANSI X9.17 Pseudorandom Number Generator (PRNG) by James Pate Williams, Jr. BA, BS, MSwE, PhD

In this blog post we give some information about my implementation of a C# triple-DES stream cipher using the ANSI X9.17 pseudorandom number generator of 5.11 Algorithm in the Handbook of Applied Cryptography by Alfred J. Menezes, ET AL. page 173. This is about as close as I can come to a one time pad (perfect security) utilizing a triple-DES based function for key generation. I suspect the security is pretty tight as long as one does not stupidly reuse a key. Recall from my previous blogs on the ANSI X9.17 matrix cipher that key space is 168-bits for triple-DES in E-D-E mode and an additional 128-bits in other key parameters for a total of 296-bits.

DES3 SC Encrypt

DES3 SC Encrypt Histogram

DES3 SC Encrypt Statistics

DES3 SC Decrypt Histogram

DES3 SC Decrypt Statistics

It would be nice if the index of coincidence was 0, but this index is probably satisfactory.

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Author: jamespatewilliamsjr

My whole legal name is James Pate Williams, Jr. I was born in LaGrange, Georgia approximately 70 years ago. I barely graduated from LaGrange High School with low marks in June 1971. Later in June 1979, I graduated from LaGrange College with a Bachelor of Arts in Chemistry with a little over a 3 out 4 Grade Point Average (GPA). In the Spring Quarter of 1978, I taught myself how to program a Texas Instruments desktop programmable calculator and in the Summer Quarter of 1978 I taught myself Dayton BASIC (Beginner's All-purpose Symbolic Instruction Code) on LaGrange College's Data General Eclipse minicomputer. I took courses in BASIC in the Fall Quarter of 1978 and FORTRAN IV (Formula Translator IV) in the Winter Quarter of 1979. Professor Kenneth Cooper, a genius poly-scientist taught me a course in the Intel 8085 microprocessor architecture and assembly and machine language. We would hand assemble our programs and insert the resulting machine code into our crude wooden box computer which was designed and built by Professor Cooper. From 1990 to 1994 I earned a Bachelor of Science in Computer Science from LaGrange College. I had a 4 out of 4 GPA in the period 1990 to 1994. I took courses in C, COBOL, and Pascal during my BS work. After graduating from LaGrange College a second time in May 1994, I taught myself C++. In December 1995, I started using the Internet and taught myself client-server programming. I created a website in 1997 which had C and C# implementations of algorithms from the "Handbook of Applied Cryptography" by Alfred J. Menezes, et. al., and some other cryptography and number theory textbooks and treatises.

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