Paper Title
Hybrid Cryptosystem For Data Security

With the fast progression of information exchange in electronic way, security is becoming more important in information transmission as well as in storage. To protect the confidential data from unauthorized access, many cryptographic algorithms were used in many research areas. Then, analyzing and optimizing many cryptographic algorithms was also performed to obtain better performance in their systems. Nowadays, hybrid cryptosystems are also developed to fulfill the security requirements. This work also proposes hybrid cryptosystem for data security in order to meet the security requirements: confidentiality, authentication, data integrity and non-repudiation. To create the hybrid cryptosystem, the secret message is encrypted by using Rivest Cipher-6(RC6) and calculated hash value by using Message Digest-5(MD-5). Then, the combination of encrypted message and hash value is encrypted by using optimized NTRU (Number Theory Research Unit) with the help of sender’s private key. Moreover, this work also focuses on the optimization of NTRU (Number Theory Research Unit) to obtain better execution speed for the hybrid cryptosystem. Index Terms- Hybrid cryptographic system, NTRU public key cryptosystem, MD-5 hash function, RC6 symmetric key cryptosystem, optimized NTRU.