I'm looking at two major RSA encryption standards:
The second one can use different hashing functions to create a hash of encoding parameters and then verify the hash at decoding step. PKCS 1.5 doesn't have this additional integrity check, and that's why security wise it's inferior to RSA OAEP/SHA1 and RSA OAEP/SHA256.
Is there a significant difference between latter two from a security point of view? How the fact that SHA1 has a collision problem can be practically exploited here? Can this SHA1 vulnerability be used, e.g. to facilitate known plain text attacks?
My impression is that using SHA1 is secure here, just like in PBKDF2/HMAC-SHA1 cases, but please share your thoughts.