Re: MessageID wording paranoia

[William Lewis <[e-mail]>]

William H. Geiger III <[e-mail]> writes:
> I had not thought of leaking key data this way. If the group feels this is
> a real concern couldn't the same type of "leaking" be done with the
> "boundary" in the MIME headers?

Or with the session key or IV, or the padding of the key to the RSA modulus  
size, or the 'k' parameter of a DSS signature, or probably any number of  
subtler ways. Fields which by their nature must *not* be generated in an  
externally predictable way.

I may be missing something here, but it seems to me that attempting to write  
this specification to completely disallow subliminal/covert channels is a  
fool's errand. It's already necessary that the PGP implementation be trusted.  
Adding requirements such as this one (specifying that the MessageID be  
externally verifiable) makes the spec more complicated and more difficult to  
implement, but doesn't actually increase security at all.

Wim Lewis / [e-mail]