[AccessD] RC1 encryption - was Re: Field Level AES Encryption

Gustav Brock Gustav at cactus.dk
Fri Apr 29 10:46:08 CDT 2011


Hi John

Yes, here: 

  http://www.frez.co.uk/vb6.aspx 

/gustav


>>> jwcolby at colbyconsulting.com 29-04-2011 17:36 >>>
Thanks for the heads up on that.  Have you by any chance found an opensource for this that is considered secure?

John W. Colby
www.ColbyConsulting.com 

On 4/29/2011 11:07 AM, Gustav Brock wrote:
> 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





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