Cryptographic hashes are "non-reversible" too. But they're both vulnerable to offline dictionary attacks if the attacker obtains the host's secrets -- which I think is what `astroduck' was really asking about, leaked server databases like this news story.
(I don't see how there's any possible protocol that behaves otherwise: if Alice is capable of proving she possesses a secret to Bob through a protocol, then Bob can always discover Alice's secret by playing that protocol with himself, enumerating every possible secret until the protocol succeeds. And so can anyone who knows everything that Bob knows about Alice's secret.)
The SRP paper doesn't say much about this except that brute-force dictionary attacks are "expensive". I don't think they make specific claims about computational hardness like scrypt. The paper was written in 1997.
"An attacker who captures the host's password file cannot directly compromise user-to-host authentication and gain access to the host without an expensive dictionary search."
(I don't see how there's any possible protocol that behaves otherwise: if Alice is capable of proving she possesses a secret to Bob through a protocol, then Bob can always discover Alice's secret by playing that protocol with himself, enumerating every possible secret until the protocol succeeds. And so can anyone who knows everything that Bob knows about Alice's secret.)
The SRP paper doesn't say much about this except that brute-force dictionary attacks are "expensive". I don't think they make specific claims about computational hardness like scrypt. The paper was written in 1997.
"An attacker who captures the host's password file cannot directly compromise user-to-host authentication and gain access to the host without an expensive dictionary search."
http://srp.stanford.edu/ndss.html