Hash-Signature

The goal is to provide a legally method that ensures the authenticity of a resource.

Let h be the generated hash, H the Hash Function, s the signature, S the signing function, and sk_A be the secret key.

We can now apply the following scheme to sign a message m:

\begin{align} h &= H(m) \\ s &= S(h, sk_A) \end{align}

To verify the signature we need the verification function V and the public key pk_A:

\begin{align} h' &= H(m) \\ h &= V(s,pk_A) \end{align}

If h' = h the message is authentic.