Suppose we throw a regular password into scrypt to generate some data. Scrypt allows us to specify how large the output data should be.
My question is, to take an extreme case, if we ask for a 1 GB data from scrypt, would it be possible somehow quickly to generate the final bytes of this output from the first bytes?
In other words, is there a threshold "x bytes" at which I "should probably not ask scrypt for more than x bytes"?
Update: Let me put it a different way: If I tell scrypt to produce 1 GB of data, make the first x bytes of the result available to the public, and use the final 48 bytes (as key and IV) to encrypt sensitive data using AES-256-CBC, am I in trouble? Trouble, in the sense that I have defeated the purpose of using scrypt? Does the answer depend on x?