Symmetric key (Shared key), Message Digest, SOA, Digital Signature, Forensic Analysis.

Abstract:
Security in Internet systems has become increasingly important in recent days. Distributed Denials of Service (DDoS) attacks are rapidly mounted by cyber criminal people to extort money from online business. The Distributed Denial of Service (DDoS) of attacks normally targeted at a particular service provider to exhaust the network and system resources of the provider.
We can category the DDoS attacks as large-scale attack and medium scale attack. The large-scale attacks increasingly take care by the Internet Service Provider (ISP). In general the medium scale attack normally may not operated by Internet Service Provider (ISP). As a result, the victim of the attack is left to deal with the attack on its own accord. This paper proposes a start of authority and forensic analysis approach to build a system against Distributed Denial of Service attacks targeting online businesses (medium scale attacks).
Attack can be identifies as using online Authentication token using message Digest and Digital Signature and as using off line Authentication called Forensic analysis. The authentication concept uses shared key along with message digest to create digital signature, so here authentication mechanism uses secure hash function for message digest and RSA digital signature standard for digital signature. Shared key generated with help of Pseudo random generator with prime number as random key.
In Forensic analysis, the Investigative process of digital forensics can be divided into two stages, first examining attacker IP Address, Time Stamp and log file of digital signature from database. Second stage is analysis of examined data, based on evidence the conclusion will draw.
K.S.RANGASAMY COLLEGE OF TECHNOLOGY
R.Kavitha & C.Ragaprabha