Re: RIPEMD -160 using .NET

On Jun 20, 4:06 am, Kelly Ethridge <k...@xxxxxxxxxxxxxxxxx> wrote:
Only the original MD4 based RIPEMD has been broken. RIPEMD-160 is still
secure.



Valery Pryamikov wrote:
On Jun 18, 6:02 am, "Divyesh" <divyesh.s...@xxxxxxxxxxxx> wrote:
Hello,

I want to use RIPE MD-160 hash algorithm from C#.NET.
Is the algo. support already available in standard.net framework (as direct
class is not supported like other hash algorithm, may be some configuration
etc.)?

Hi,
You are correct that paper of Wang describes attack on original
RIPEMD. However RIPEMD-160 shares design methodology with MD-family of
hashes and is based on unbalanced feistel networks. RIPEMD-160 has
just added few rounds, changed some constants plus some other minor
changes, but the structure is generally the same. As far as I
understand it - Wang at al. has developed a generalized way of
attacking UFN based hashes - the result is series of published attacks
on most used UFN-based hashes including SHA1 (which btw has more
differences from MD-family than RIPEMD-160). So, "no attack on
RIPEMD-160 has been published in a paper by Wang in 2004" is much more
different than "it is still secure"!
BTW SHA2 has more done even more changes of design from MD family than
either SHA1 or RIPEMD-160 (some of these changes could be considered
as radical changes). And there is another hash algorithm Whirlpool
that is based on completely different methodology (it is based on the
design of AES encryption algorithm) which is a recommended hash
algorithm from Nessie project (New European Schemes for Signatures,
Integrity, and Encryption: http://www.cosic.esat.kuleuven.ac.be/nessie/)
and that is probably one of the best hash candidates so far. So, if I
would need to bet on hash - I'd rather use Whirlpool, SHA2 (or even
SHA1) than RIPEMD - family of hashes (also see NIST policy on hashes:
http://www.csrc.nist.gov/pki/HashWorkshop/NIST%20Statement/NIST_Policy_on_HashFunctions.htm)
It could also be a very good idea to watch for hash candidates for
NIST hash contest here: http://www.csrc.nist.gov/pki/HashWorkshop/index.html

-Valery

.

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