Why I think using sha256crypt or sha512crypt is dangerous
&gt; What this clearly demonstrates, is that the only factor driving execution time, is the number of iterations you apply to the password, before delivering the final password hash.<p>Isn&#x27;t the reason this is true that bcrypt just truncates the input at 72 characters?  And if that&#x27;s correct, aren&#x27;t there basically a few options, any of which basically invalidate the argument?<p>1. Enforce a password length limit.  Fixes the unbounded growth of the shacrypt CPU time while simultaneously ensuring bcrypt is not ignoring input.<p>2. Pre-hash the input to bcrypt by passing it through SHA512.  Makes bcrypt now grow in the exact same way as shacrypt.<p>3. Don&#x27;t enforce a password limit, but truncate the password.  Fixes the CPU time.<p>I don&#x27;t know enough about bcrypt in practice to know which of those options is most commonly advised, but it just seems like a bit of a strawman here.  Passing 4096 bytes to bcrypt is the same as passing 72 bytes to bcrypt because it ignores the last 4024 bytes right?