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Is the password verifier in SRP actually hashed?
Like most PAKE protocols, SRP has two phases. In the sign-up phase, the user registers a “password verifier” with the server. This value is not actually the password itself. It’s not even the hashed password. It’s actually a one-way function of the hashed password, of the form computed using a Diffie-Hellman-like process.
Do you use opaque or opaque for SRP?
But it’s inefficient and you should use OPAQUE. Like most PAKE protocols, SRP has two phases. In the sign-up phase, the user registers a “password verifier” with the server. This value is not actually the password itself.
What’s the difference between SRP and early Pakes?
SRP does some stuff “right”. For one thing, unlike early PAKEs it does not require you to store a raw password on the server (or, equivalently, a hash that could be used by a malicious client in place of the password). Instead, the server stores a “verifier” which is a one-way function of the password hash.
Is there a security proof for the SRP protocol?
The fact of the matter is that SRP is a relatively simple PAKE protocol. It should be possible to provide a strong security proof, and yet SRP has none. This is not a good situation for a widely-used protocol to be in. What about elliptic curves?
What should you know about the SRP protocol?
The first thing you should notice is that SRP is, at its heart, basically an extension of the Diffie-Hellman protocol. The server picks a value , the client picks , and the two end up with some function of .
Why is SRP obscured in the first message?
Thankfully in the first message of SRP this value is obscured due to the fact that it is multiplied by a constant (which does nothing), and is then added to , where is chosen at random. Provided that both of are chosen correctly, this should serve to protect it reasonably well.
Is the SRP paper a proof of security?
The original SRP paper claims contains a section discussing the security of the protocol. Unfortunately, this analysis doesn’t really contain a proof of security. Instead, it mostly talks about attacks.