Elliptic Curve Digital Signature Algorithm

Advantages of ECDSA over DSA

ECDSA is a very attractive algorithm for implementing EDS. The most important advantage of ECDSA is its ability to work on much smaller fields {\displaystyle F_{p}}F_{p}. As with elliptic curve cryptography in general, the bit size of the public key that will be needed for ECDSA is assumed to be twice the size of the private key in bits. In comparison, with a security level of 80 bits (meaning an attacker needs approximately {\displaystyle 2^{80}}2^{80} signature versions to find the private key), the DSA public key size is at least 1024 bits, while the ECDSA public key is 160 bits. On the other hand, the signature size is the same for both DSA and ECDSA: {\displaystyle 4t}4t bits, where {\displaystyle t}t is the security level measured in bits, i.e. approximately 320 bits for a security level of 80 bits.