Yes, Mohammed, I want to prevent the colisions. MD5 is not as resistant as
SHA-1, while co-author of SHA-1 is NSA, so we are not 100% sure, if they
have this alg. cracked, but is good rated anyway! Crypto++ contains 2
different types, i.e. RSA-ES for encryption and RSA-SS for signature. You
say that I can use RSA-ES, that is intended for encryption and sign the
combined hash using its private key? The truth is I am not sure how to do
it...


Haytham Mohammed wrote:
> 
> Hi Jakub
>    
>   What is your reference for this idea? (it is a creative one :) )
>   I think it will be more secure since the collision resistance will be
> increased.
>    
>   you are going to hash the message twice
>   1-once with SHA and other with MD5 
>   2-then concat the 2 hashes
>   3-then encrypt the result from 2 using your private key (using RSA)
>   4- the result from 3 is the signature :)
>    
>   Regards
>   Haytham Mohammed
>   
> Jakub <[EMAIL PROTECTED]> wrote:
>   
> Does anybody know, how to combine i.e. SHA + MD5 hashes in one signature
> (i.e. RSA)? I know that there may be 2 separated signatures, but it should
> be more secure and efficient having 2 hashes in one signature.
> Thanks, Jakub
> -- 
> View this message in context:
> http://www.nabble.com/SHA-MD5-Combination-tf2192153.html#a6066434
> Sent from the Crypto++ forum at Nabble.com.
> 
> 
> 
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