[cryptography] XTS mode

2013-09-28 Thread Jonathan Thornburg
On Sat, 28 Sep 2013, Mansour Moufid wrote: > XTS-AES must be rekeyed after each terabyte; [[...]] This reminds me of a question I wanted to ask the more knowledgable crypto-folk on this list: What is currently known about the security of AES-XTS mode? Is there a good up-to-date survey paper some

Re: [cryptography] The Unbreakable Cipher

2013-09-28 Thread Mansour Moufid
On Wed, 2013-09-25 at 10:11 -0400, John Young wrote: > [Answer to the question:] "Does there exist an unbreakable cipher" > would be this, "Every cipher is breakable, given enough traffic, and > every cipher is unbreakable, if the traffic volume is restricted > enough." > > [End quote] > > Is

Re: [cryptography] One Time Pad Cryptanalysis

2013-09-28 Thread Lodewijk andré de la porte
(AFAIK) Secure OTP depends on two things: 1. Good source. P[i] must be independent to anything in P nor to the method to generate P. "Random", you'd typically say. Fully unpredictable might be more clear (given people's unclarity about what's random). 2. No leak of P Reuse of P leaks P when the

Re: [cryptography] Asynchronous forward secrecy encryption

2013-09-28 Thread Jeffrey Walton
On Sat, Sep 28, 2013 at 7:36 AM, ianG wrote: > ... >>> The key reuse issue isn't related to the choice between time-based and >>> message-based updates. It's caused by keys and IVs in the current design >>> being derived deterministically from the shared secret and the sequence >>> number. If an e

Re: [cryptography] One Time Pad Cryptanalysis

2013-09-28 Thread John Young
This is simply treasonous. Security clearance voided. You be squished soon by boot stomper for 1%. At 07:40 AM 9/28/2013, you wrote: They should be given something that won't screw up. Which means it needs to be simple enough such that all the decisions are already made. In my work, I've evo

Re: [cryptography] One Time Pad Cryptanalysis

2013-09-28 Thread ianG
On 26/09/13 23:09 PM, Jeffrey Goldberg wrote: I’m suggesting that when offering advice to application developers on what sorts of systems to use, we should explicitly consider how easy it is for them to screw it up and how bad things get when they do. They should be given something that won

Re: [cryptography] Asynchronous forward secrecy encryption

2013-09-28 Thread ianG
Some thoughts... On 26/09/13 23:08 PM, zooko wrote: Let me just mention that this conversation is AWESOME. I only wish the folks over at Perry's Crypto List (http://www.metzdowd.com/pipermail/cryptography/) knew that we were having such a great conversation over here. On Thu, Sep 19, 2013 at 09