> What I think we are worried about here are very widespread > automated attacks, and they're passive (data is collected and > then attacks are run offline). All that constrains what attacks > make sense in this context.
John Kelsey discusses several attacks that might fit this profile but one he did not consider was: - A backdoor that leaks cryptographic secrets consider for example applications using an intel chip with hardware-assist for AES. You're feeding your AES keys directly into the cpu. Any attacker controlling the cpu has direct access and doesn't have to do any fancy pattern matching to discover the keys. Now if that CPU had a way to export some or all of the bits through some channel that would also be passively observable, the attacker could pull off an offline passive attack. What about RNG output? What if some bits were redundantly encoded in some of the RNG output bits which where then used directly for tcp initial sequence numbers? Such a backdoor would be feasible. -- Tim Newsham | www.thenewsh.com/~newsham | @newshtwit | thenewsh.blogspot.com _______________________________________________ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography
