I've started a matrix of ways that an immutable file cap format could break: http://allmydata.org/trac/tahoe/wiki/NewCaps/WhatCouldGoWrong
Unfortunately I can't conveniently replicate the data into an email message (except by sending HTML-formatted email, which I assume most of you would hate and which I don't even know how to do). So go read this page! http://allmydata.org/trac/tahoe/wiki/NewCaps/ WhatCouldGoWrong It includes how expensive it is to brute-force each part, which show us how big the crypto values R and T need to be. Also pay attention to the "what crypto property do we rely on" column. I wouldn't be surprised if SHA-256's collision-resistance is increasingly called into question in future years. (On the other hand I would be rather shocked if SHA-256's second-pre-image resistance were called into question in the forseeable future.) Regards, Zooko _______________________________________________ tahoe-dev mailing list [email protected] http://allmydata.org/cgi-bin/mailman/listinfo/tahoe-dev
