Re: HMAC-SHA-1 security question

On 22 Mar, 19:00, osmo....@xxxxxxxxx wrote:
Hi
I'd have an interesting question.

We know that HMAC-SHA 1 is a hash value H, computed from a base input
value V and a secret key K.
In formula: H = HAMC-SHA-1(K, V).

Now, let us assume an attacker knows H and V. Only the K is unknown.
I'd like to know if there was any possibility to make conclusions
about the secret key K?
Or, furthermore, do values for H and V exist that make it possible to
conclude about K? Even if it was just one bit one can make conclusions
about? Any ideas?

Please, I'd like to hear some input on this from somebody...

I suppose that if there exists a method capable of recovering the key
with less effort than brute-force then it will imply that SHA-1 is
broken.
.

Relevant Pages

  • HMAC-SHA-1 security question
    ... We know that HMAC-SHA 1 is a hash value H, computed from a base input ... value V and a secret key K. ...
    (sci.crypt)
  • Re: HMAC-SHA-1 security question
    ... We know that HMAC-SHA 1 is a hash value H, computed from a base input ... value V and a secret key K. ... let us assume an attacker knows H and V. ... If such an attack were found it would be major cryptographic news, and mean that SHA-1 is completely and utterly broken. ...
    (sci.crypt)