Re: [tor-dev] Even more notes on relay-crypto constructions

2012-10-18 Thread Nick Mathewson
On Thu, Oct 18, 2012 at 11:18 PM, Mike Perry wrote: > Thus spake Nick Mathewson (ni...@alum.mit.edu): > >> On Thu, Oct 18, 2012 at 6:10 PM, Mike Perry wrote: >> [...] >> >> There are modes that are supposed to prevent this, and applying them >> >> to a decent wide-block cipher might solve the is

Re: [tor-dev] Even more notes on relay-crypto constructions

2012-10-18 Thread Mike Perry
Thus spake Nick Mathewson (ni...@alum.mit.edu): > On Thu, Oct 18, 2012 at 6:10 PM, Mike Perry wrote: > [...] > >> There are modes that are supposed to prevent this, and applying them > >> to a decent wide-block cipher might solve the issue. IGE is one of > >> them [IGE], but it turns out to be b

Re: [tor-dev] Even more notes on relay-crypto constructions

2012-10-18 Thread Nick Mathewson
On Thu, Oct 18, 2012 at 6:10 PM, Mike Perry wrote: [...] >> There are modes that are supposed to prevent this, and applying them >> to a decent wide-block cipher might solve the issue. IGE is one of >> them [IGE], but it turns out to be broken by an attacker who knows >> some plaintext. The Accu

Re: [tor-dev] Even more notes on relay-crypto constructions

2012-10-18 Thread Mike Perry
Thus spake Nick Mathewson (ni...@torproject.org): > I should share with the list an update of where I am with a design for > an improved relay crypto protocol. For background and motivation, > please see the last thread on the topic [Prop202]. > > There are three main questions remaining for me