# Tag Info

First of all, let us explore what a "length extension attack" is; it might not be exactly what you assumed it was. Suppose we were given the MD5 hash of a bytestring we'll call $A$; we may have no idea what the string $A$ consists of, but we do know its length. Then, we can create a bytestring $B$ (which depends on the length of $A$, but not any of its ...