Security, Math, Cryptography.
multiplication is commutative, R is commutative ring. If there is a neutral element for the multiplication, R is a ring with identity: ∃ e ∈ R, ∀ x ∈ R, x ⋅ e = x As example, ℝ is also a ring (a commutative ring with identity even) where the second operation is × (the multiplication we all know),