Secure Hybrid Mode-Based Cryptosystem | Science Publications

American Journal of Applied Sciences

E. S. Ismail¹  S. Baharudin¹ 

关键词: Cryptology;    cryptography;    cryptosystem;    hard problems;   

DOI  :  10.3844/ajassp.2012.289.292

学科分类：自然科学（综合）

来源: Science Publications

【 摘 要 】

Problem statement: A cryptosystem provides two parties; a sender and a receiver tocommunicate interactively via an insecure channel in which, the sender is able to send any confidentialmessage, document or data in a disguised form to the intended receiver. Upon receiving the disguisedmessage, the receiver converts it to the intelligible message using his secret key. The security of theexisting cryptosystems was based on a single hard problem such as factorization, discrete logarithm,quadratic residue, or elliptic curve discrete logarithm. Although these schemes appear secure, one dayin a near future they may be broken if one finds a solution of a single hard problem. Approach: Toovercome the disadvantage of using a single hard problem, we developed a secure hybrid mode-basedcryptosystem based on the two well-known hard problems; factoring and discrete logarithm. We injectthe element of the hard problems into our encrypting and decrypting equations respectively in such away that the former equation depends on two public keys whereas the latter depends on twocorresponding secret keys. Results: The new cryptosystem is shown heuristically secure against various algebraic attacks. The efficiency analysis confirms that our scheme only needs 3T_exp+T_hash time complexity for encryption and 2T_exp time complexity for decryption and this magnitude of complexity is considered minimal for multiple hard problems-like cryptosystems. Conclusion: The newly developed hybrid mode based-cryptosystem provides greater security level than that schemes based on a single hard problem. The enemy or adversary has to solve the two problems simultaneously which is unlikely to happen in order to read any secret message.

【 授权许可】

Unknown