Highdegree compression functions on alternative models of elliptic curves and their applications
Abstract
This paper presents method for obtaining highdegree compression functions using natural symmetries in a given model of an elliptic curve. Such symmetries may be found using symmetry of involution $[1]$ and symmetry of translation morphism $\tau_T=P+T$, where $T$ is the $n$torsion point which naturally belongs to the $E(\mathbb K)$ for a given elliptic curve model. We will study alternative models of elliptic curves with points of order $2$ and $4$, and specifically Huff's curves and the Hessian family of elliptic curves (like Hessian, twisted Hessian and generalized Hessian curves) with a point of order $3$. We bring up some known compression functions on those models and present new ones as well. For (almost) every presented compression function, differential addition and point doubling formulas are shown. As in the case of highdegree compression functions manual investigation of differential addition and doubling formulas is very difficult, we came up with a Magma program which relies on the Gröbner basis. We prove that if for a model $E$ of an elliptic curve exists an isomorphism $\phi:E \to E_M$, where $E_M$ is the Montgomery curve and for any $P \in E(\mathbb K)$ holds that $\phi(P)=(\phi_x(P), \phi_y(P))$, then for a model $E$ one may find compression function of degree $2$. Moreover, one may find, defined for this compression function, differential addition and doubling formulas of the same efficiency as Montgomery's. However, it seems that for the family of elliptic curves having a natural point of order $3$, compression functions of the same efficiency do not exist.
 Publication:

arXiv eprints
 Pub Date:
 November 2021
 arXiv:
 arXiv:2111.04533
 Bibcode:
 2021arXiv211104533W
 Keywords:

 Computer Science  Cryptography and Security
 EPrint:
 33 pages