The vector decomposition problem (VDP) has been proposed as a computational problem on which to base the security of public key cryptosystems. We give a generalisation and simplification of the results of Yoshida on the VDP. We then show that, for the supersingular elliptic curves which can be used in practice, the VDP is equivalent to the computational Diffie-Hellman problem (CDH) in a cyclic ...

In this paper we discuss various aspects of cryptosystems based on hyperelliptic curves. In particular we cover the implementation of the group law on such curves and how to generate suitable curves for use in cryptography. This paper presents a practical comparison between the performance of elliptic curve based digital signature schemes and schemes based on hyperelliptic curves. We conclude t...

Elliptic curve cryptosystems, proposed by Koblitz ((11]) and Miller ((15]), can be constructed over a smaller eld of deenition than the ElGamal cryptosystems ((5]) or the RSA cryptosystems ((19]). This is why elliptic curve cryptosystems have begun to attract notice. In this paper, we investigate eecient elliptic curve exponentiation. We propose a new coordinate system and a new mixed coordinat...

In 1987 Neil Koblitz first suggested the use of Elliptic curves for Public Key Cryptosystems. This has triggered publications about ECC (Elliptic Curve Cryptography) in recent years as well as the appearance of first University textbooks about that topic. Some Mathematicians and Computer Scientists have focused their studies of Elliptic curves on efficiency and security of ECC. Questions arise ...

Elliptic curve cryptosystems, proposed by Koblitz ((12]) and Miller ((16]), can be constructed over a smaller eld of deenition than the ElGamal cryptosystems ((6]) or the RSA cryptosystems ((20]). This is why elliptic curve cryptosystems have begun to attract notice. In this paper, we investigate eecient elliptic curve exponentiation. We propose a new coordinate system and a new mixed coordinat...

Pairing-based cryptosystems depend on the existence of groups where the Decision Diffie-Hellman problem is easy to solve, but the Computational Diffie-Hellman problem is hard. Such is the case of elliptic curve groups whose embedding degree is large enough to maintain a good security level, but small enough for arithmetic operations to be feasible. However, the embedding degree for most ellipti...

We show that the elliptic curve cryptosystems based on the Montgomery-form E : BY 2 = X+AX+X are immune to the timingattacks by using our technique of randomized projective coordinates, while Montgomery originally introduced this type of curves for speeding up the Pollard and Elliptic Curve Methods of integer factorization [Math. Comp. Vol.48, No.177, (1987) pp.243-264]. However, it should be n...

The Tate pairing has plenty of attractive applications, e.g., ID-based cryptosystems, short signatures, etc. Recently several fast implementations of the Tate pairing has been reported, which make it appear that the Tate pairing is capable to be used in practical applications. The computation time of the Tate pairing strongly depends on underlying elliptic curves and definition fields. However ...

One of the main diiculties for implementing cryptographic schemes based on elliptic curves deened over nite elds is the necessary computation of the cardinality of these curves. In the case of nite elds IF2n, recent theoretical breakthroughs yield a signiicant speed up of the computations. Once described some of these ideas in the rst part of this paper, we show that our current implementation ...