I don't think it's about importance of different keys. The short nonce works better as a counter, and 8 bytes is sufficient. The long nonce could be a counter, but that's extra work to implement, and a *good* random number generator is ideal. 16 bytes may be overkill, however it's inherited from CurveCP and I don't argue with that design.
On Wed, Jul 2, 2014 at 9:29 PM, Diego Duclos <[email protected]> wrote: > Thanks a lot Pieter, I had missed that section. > I still miss the why somewhat though, is this purely to save computing power > as the transient keys are less important to protect then the permanent keys > ? And thus use shorter nonces. > > > On Wed, Jul 2, 2014 at 9:26 PM, Pieter Hintjens <[email protected]> wrote: >> >> It says, in the RFC: "We use two kinds of nonces in CurveZMQ. A long >> nonce protects permanent keys, and is 16 octets from a good random >> number generator. A short nonce protects transient keys and is an >> 8-octet sequential number." >> >> http://rfc.zeromq.org/spec:26 >> >> On Wed, Jul 2, 2014 at 9:13 PM, Diego Duclos >> <[email protected]> wrote: >> > Hello all, >> > >> > I've been reading up on the CurveZMQ and CurveCP specs. >> > I've noticed they use a mix if 8 and 16 bytes nonces, who are then all >> > passed to 24 bytes using a constant prefix. >> > I was wondering when 8 byte and when 16 byte nonces are chosen as well >> > as >> > why. >> > >> > Kind Regards, >> > >> > Diego Duclos >> > Palm Stone Games >> > >> > _______________________________________________ >> > zeromq-dev mailing list >> > [email protected] >> > http://lists.zeromq.org/mailman/listinfo/zeromq-dev >> > >> _______________________________________________ >> zeromq-dev mailing list >> [email protected] >> http://lists.zeromq.org/mailman/listinfo/zeromq-dev > > > > _______________________________________________ > zeromq-dev mailing list > [email protected] > http://lists.zeromq.org/mailman/listinfo/zeromq-dev > _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
