gpg: failed to create temporary file '/var/lib/lurker/.#lk0x583e3100.hantslug.org.uk.10555': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Thu Apr 10 18:11:02 2008 BST
gpg: using DSA key FCBBA9C8F2DEED36
gpg: Can't check signature: No public key
On Thu, Apr 10, 2008 at 03:39:25PM +0100, The Holy ettlz wrote:
> > From distant memory, DH key exchange also manages to have some
> > protection against man-in-the-middle attacks (but I could be wrong
> > about that -- my crypto books are at home).
>
> I think is because DH can also be used for digital signatures (e.g.,
> compute message hash, sender *DE*crypts that using their private key,
> receiver uses sender's public key to encrypt this and check the hash).
That doesn't make sense in the context of D-H. I think you are
confusing it with RSA where decryption and signing are the same
mathematical operation.
> This can be forged by a MITM, but the attacker would have to
> poison/intercept the sender's public key, which would more than likely
> just kill its trustworthyness. Hence public keys are normally packed
> into certificates which are checked and digitally signed by either a
> "trusted" authority (like HTTPS-enabled sites) to help ensure their
> integrity. The other approach is the PGP-style keysigning web-of-trust.
Not the only other approach - there are more exotic things like
Identity-based public key crypto (where your "identity" /is/ your
public key).
--
Andrew McDonald
E-mail: andrew@???
http://www.mcdonald.org.uk/andrew/
