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

jm.hwsn jm.hwsn at gmail.com
Fri Apr 29 10:14:26 CDT 2011


Which is the similar to using the strConv function in Access to store the
data in Unicode.
It's unreadable but not really secure.
Thanks,
Jim

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Gustav Brock
Sent: Friday, April 29, 2011 10:08 AM
To: accessd at databaseadvisors.com
Subject: [AccessD] RC1 encryption - was Re: Field Level AES Encryption

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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