DME: a full encryption, signature and KEM multivariate public key cryptosystem

DME is a multivariate public key cryptosystem based on the composition of linear and exponential maps that allow the polynomials of the public key to be of a very high degree. A previous version of DME ([3]) was presented to the NIST call for postquantum cryptosystems (in the KEM category), but it did not qualify to the second round. This new version of DME adds two extra rounds of exponentials to the first version, and only needs arithmetic in the finite fields Fq and Fq2, dispensing the need for the field Fq3

DME: a full encryption, signature and KEM multivariate public key cryptosystem

DME is a multivariate public key cryptosystem based on the composition of linear and exponential maps that allow the polynomials of the public key to be of a very high degree. A previous version of DME was presented to the NIST call (in the KEM category). The new version of DME adds one or two extra rounds of exponentials to the original two rounds. With this setting the composition gives a deterministic trapdoor one way permutation, which can be combined with an OAEP padding scheme for KEM and PSS00 for signature. In this paper we give the SUPERCOP timing of DME-OAEP and DME-PSS00 for three and four exponentials and compare them with NIST finalists. For NIST security level 5 the size of ciphertext and signature is only 64 bytes