If I reveal the HMAC of encryption key, does it weaken the secrurity of the payload ?
e.g, I would construct following security packet
cipher: bf_cbc IV: initialization vector to the cipher key-md5: md5 of the encryption key crypt-text: encrypted (md5(text) + text)
As above shown, does revealing of md5 (or some other hmac) of the key weakens the scheme ?
I would like to specifically catch the case where the keys (encryption to decryption) dont match, as oppose to decrypt the crypt-text with wrong key and then 'discover' that md5(text) dont match the text so declare corrupted security packet.