Hacker News new | past | comments | ask | show | jobs | submit login

I think I can sum up the fundamental difference between my take on crypto (run away!) and Colin's ("use OAEP padding instead of PKCS!").

When Colin thinks of crypto he thinks of things like Tarsnap, which was built and designed to embrace cryptography; cryptography is part of the reason it exists. It is not an afterthought.

When I think of crypto, it's about all the places crypto pops up in normal non-secure CRUD-webapp situations. Like the guy who uses crypto to effect single-signon without sharing databases between apps. Or the team that encrypts URLs instead of implementing access control. Or the team that uses AES to "secure" a viewstate cookie.

If your goal is to produce a system like Tarsnap, which from day one is going to receive attention from security people because it is a security tool, I have less of a problem with Colin's recommendations.

But if you're trying to build client-side database-free single signon (ab)using crypto as a tool, this slide deck is terrible. Follow every piece of advice in it and you will very likely still produce a system that is easier to break than if you hadn't used crypto.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact