@article {10.3844/ajassp.2014.171.179, article_type = {journal}, title = {CERTIFICATE AUTHORITY SCHEMES USING ELLIPTIC CURVE CRYPTOGRAPHY, RSA AND THEIR VARIANTS-SIMULATION USING NS2}, author = {Shivkumar, S. and Umamaheswari, G.}, volume = {11}, year = {2013}, month = {Dec}, pages = {171-179}, doi = {10.3844/ajassp.2014.171.179}, url = {https://thescipub.com/abstract/ajassp.2014.171.179}, abstract = {A PKI (public key infrastructure) enables users of a basically unsecure public network to securely and privately exchange data through the use of a public and a private cryptographic key pair that is obtained and shared through a trusted authority. The public key infrastructure provides for a digital certificate that can identify an individual or an organization and directory services that can store and, when necessary, revoke the certificates. Although the components of a PKI are generally understood, a number of different vendor approaches and services are emerging. The two major digital signature algorithms are Elliptic Curve Digital Signature Algorithm (ECDSA) which is the elliptic curve analogue of the Digital Signature Algorithm (DSA) and RSA algorithm. The two algorithms are used for generating the certificates exchanged between computer systems. Elliptic curve based systems can give better security compared to RSA with less key size. This study compares the performance of ECC based signature schemes and RSA schemes using NS2 simulation. It is observed that ECC based certificate authority schemes gives better speed and security. Elliptic curve based schemes are the best for time and resource constrained wireless applications.}, journal = {American Journal of Applied Sciences}, publisher = {Science Publications} }