In contrast to non-commutative cryptography , the currently widely used public - key cryptosystems like RSA cryptosystem , Diffie -- Hellman key exchange and elliptic curve cryptography are based on number theory and .
Depend on commutative algebraic structures .
In contrast to non-commutative cryptography , the currently widely used public - key cryptosystems like RSA cryptosystem , Diffie -- Hellman key exchange and elliptic curve cryptography are based on number theory and hence depend on commutative algebraic structures .