crypto.graphics

Message Authentication Code (MAC) Security Game

{Sign, Verify} is the candidate MAC scheme.

	k = rand(Keys)
i++	m_i	←	m_i ∈ Inputs
i++	t_i = Sign(k, m_i)	→	t_i
			(m^, t^) ∈ Outputs: (∀ i) (m^, t^) ≠ (m_i, t_i)
			(m^, t^) ↓

Advantage

Advantage(Adversary) = Pr[Verify(k, m^*, t^*) accepts the tag as valid]

Correctness

(∀ m) Pr[k ← genKeys(), Verify(k, m, Sign(k, m)) == accept ] == 1