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I get that you need to learn how to break software as a major part of the learning process. I also understand that a broken system often can't be fixed, and tha

by phaus 13y ago

I get that you need to learn how to break software as a major part of the learning process. I also understand that a broken system often can't be fixed, and that if your system breaks you might have to start from scratch. But does one go from becoming an expert at breaking systems to automatically churning out a secure cryptographic system? Or does one become an expert at breaking and then build a bunch of flawed crypto systems, as the learning process continues? Maybe the process is just counterintuitive, but it seems that no matter how skilled someone might be at breaking systems, that building a sound system on the first try would still be incredibly difficult. I know that crypto systems aren't built iteratively, instead I'm talking about going back to the drawing board each time. Would there be value in that, or would it be a waste of time? I'm not yet an expert (and I am well aware that you are), though I aspire to be one day. Perhaps you would be kind enough to elaborate?

daeken 13y ago
> But does one go from becoming an expert at breaking systems to automatically churning out a secure cryptographic system? Or does one become an expert at breaking and then build a bunch of flawed crypto systems, as the learning process continues? Both and neither. Once you get really good at breaking cryptosystems, designing them looks very similar. You start with best practices: use sane primitives (or thoroughly vetted components, preferably!) and put them together in known, simple (simple is key) ways. Then you put on your breaking hat and you attempt to violate every constraint. If you find a flaw, then you iterate or redesign. Once you are happy with it, you start showing it to other crypto breakers, until they're happy with it too. At this point, you have something that would withstand most basic attacks, and you might be ready to put it out into the world. It's still not battle-hardened and ready for uberconfidential data, but it's in a better state than most cryptosystems. As more and more people look at it without owning it, its trustworthiness goes up, and the risk goes down. Secure cryptosystems don't pop out of nothing; they're iterative, but not in the "I should do a Show HN" sense. It's iterative like writing a poem -- you don't release it one line at a time.

by phaus 13y ago

daeken 13y ago

> But does one go from becoming an expert at breaking systems to automatically churning out a secure cryptographic system? Or does one become an expert at breaking and then build a bunch of flawed crypto systems, as the learning process continues? Both and neither. Once you get really good at breaking cryptosystems, designing them looks very similar. You start with best practices: use sane primitives (or thoroughly vetted components, preferably!) and put them together in known, simple (simple is key) ways. Then you put on your breaking hat and you attempt to violate every constraint. If you find a flaw, then you iterate or redesign. Once you are happy with it, you start showing it to other crypto breakers, until they're happy with it too. At this point, you have something that would withstand most basic attacks, and you might be ready to put it out into the world. It's still not battle-hardened and ready for uberconfidential data, but it's in a better state than most cryptosystems. As more and more people look at it without owning it, its trustworthiness goes up, and the risk goes down. Secure cryptosystems don't pop out of nothing; they're iterative, but not in the "I should do a Show HN" sense. It's iterative like writing a poem -- you don't release it one line at a time.