Gustav Brock
Gustav at cactus.dk
Fri Apr 29 10:07:53 CDT 2011
Oops John, you missed my follow-up message: --- Hi all I was told by one who knows more about encryption than me, Dave Howe, that: <quote> PC-1 is an important part of the DES algorithm, used to prescramble the bit ordering on the key (and remove the parity bits) before starting the first round of the non-invertible s-boxes. These are also left-rotated between each round (by 1 or 2 bits, in a non-regular pattern) to form what is commonly called a "key schedule" or "subkey array". However your module is not using DES/PC-1, but "Pukall Code #1" which is a code Alexander Pukall designed himself - and which is widely regarded as insecure. Pukall shouldn't really have chosen the same name as the DES key schedule, as it does tend to cause confusion. </quote> So, as a general warning, the code is fine for making clear text non-readable but should not be used for true encryption. --- /gustav >>> jwcolby at colbyconsulting.com 29-04-2011 17:00 >>> Thanks to Gustav. this is encryption, not hashing. Option Compare Database Option Explicit ' PC1 Cipher 128-bit key ' (c) Alexander Pukall 1991