Optimized Security of Wireless Sensor Networks Based on a Modified Nk Cryptosystem

Security in the wireless sensor networks (WSNs) is based on using public-key cryptosystems such as RSA cryptosystem to achieve the authentication between wireless sensor nodes and their base station. This cryptosystem has two important problems; (i) the decryption process is slow (ii) it is insecure due to some known attacks such as common modulus attack and low exponent attack. In this paper we modify the encryption algorithm of the NK cryptosystem to avoid the problems of the RSA cryptosystem. We prove that standard attacks that applied on the RSA cryptosystem are not applicable on the NK cryptosystem after our modification.