Cryptography-Digest Digest #494, Volume #14 Sat, 2 Jun 01 02:13:00 EDT
Contents:
Re: Question about credit card number (those who know me have no need of my name)
Re: Question about credit card number ("Jeffrey Walton")
----------------------------------------------------------------------------
From: those who know me have no need of my name <[EMAIL PROTECTED]>
Subject: Re: Question about credit card number
Date: 02 Jun 2001 02:42:54 GMT
<[EMAIL PROTECTED]> divulged:
>Even if the CC numbers are stored in an encrypted form in the back ends,
>they are easy to break since all of CC numbers are encrypted using the
>same master key. Isn't it right?
it's not a given. it may be that part of the key is generated using
data from the customer. (that's not to say that enough key is likely
obtained from the customer so as to prevent an attack against the
data.)
--
okay, have a sig then
------------------------------
Reply-To: "Jeffrey Walton" <[EMAIL PROTECTED]>
From: "Jeffrey Walton" <[EMAIL PROTECTED]>
Subject: Re: Question about credit card number
Date: Fri, 1 Jun 2001 23:44:52 -0400
: What the heck does that mean? asymmetric ciphers solve different
problems
: then symmetric ones.
I knew I was going to get flamed for that.
See Schneier, Applied Cryptography, Chapter 7, Section 3 on page 165 and
the accompanying table 7.9.
Jeff
"Tom St Denis" <[EMAIL PROTECTED]> wrote in message
news:PyYR6.6517$[EMAIL PROTECTED]...
:
: "Jeffrey Walton" <[EMAIL PROTECTED]> wrote in message
: news:3b1850bd$0$[EMAIL PROTECTED]...
: > : Even if the CC numbers are stored in an encrypted form in the back
: > ends,
: > : they are easy to break since all of CC numbers are encrypted using
the
: > : same master key. Isn't it right?
: >
: > Lu, you can claim the prizes now...
: >
: > http://www.rsasecurity.com/rsalabs/challenges/factoring/index.html
: >
: > :)
: >
: > They could also be encrypted with symmetric keys, which is basically
: > just as hard. For example, a symmetric key with length x is
: > approximately as secure an asymmetric key length of y.
:
: What the heck does that mean? asymmetric ciphers solve different
problems
: then symmetric ones.
:
: That's like saying y grams of potassium is approximately as good as x
grams
: of sodium.
:
: Tom
:
------------------------------
** FOR YOUR REFERENCE **
The service address, to which questions about the list itself and requests
to be added to or deleted from it should be directed, is:
Internet: [EMAIL PROTECTED]
You can send mail to the entire list by posting to sci.crypt.
End of Cryptography-Digest Digest
******************************
