An approach for generating different types of gray codes

Given a certain Gray code consisting of 2n codewords, it is possible to generate from it n! 2n codes by permuting and/or complementing the bits in all the codewords in the same manner. The codes obtained this way are all defined to be of the same type. An approach for converting the standard Gray code (known as the reflected code) into other Gray codes of different types is presented in this paper. A systematic way of generating, for example, all types of Gray codes consisting of 16 codewords is given

SELF-CERTIFIED PUBLIC KEY CRYPTOGRAPHY FOR RESOURCE-CONSTRAINED SENSOR NETWORKS

Abstract. As sensor networks continue to become one of the key technologies to realize ubiquitous computing, promising to revolutionize our ability to sense and control the physical environment, security remains a growing concern. The resource-constrained characteristics of sensor nodes, the ad-hoc nature of their deployment, and the vulnerability of wireless communications in general pose a need for unique solutions. A fundamental requisite for achieving security is the ability to encrypt and decrypt con…dential data among arbitrary sensor nodes, necessitating the generation of joint private keys. Although the advantage of public key cryptographic key-generation is widely acknowledged, o¤ering scalability and decentralized management, the scarce resources of sensor networks render the applicability of public key methodologies highly challenging. In this respect, Elliptic Curve Cryptography (ECC) has emerged as a suitable public key cryptographic foundation in constrained environments, providing high security for relatively small key sizes. Recent results indicate that the execution of ECC operations in sensor nodes is feasible. In an e¤ort to promote practical adoption of ECC-based key-generation in sensor networks, this paper presents a comprehensive security methodology that signi…cantly reduces the overall communication and computation e¤orts involved. The technology developed has been implemented on Intel Mote2 platforms at the University of Tennessee. The encouraging performance results obtained accentuate the practicality and scalability properties of the proposed approach. Key words. Security in wireless sensor networks, resource-constrained cryptography, selfcerti…ed key generation, Intel Mote

Self-Certified Public Key Generation for Resource-Constrained Sensor Networks

Abstract – It is widely acknowledged that security will play a key role in the successful design and deployment of wireless sensor networks (WSN). A prerequisite for achieving security is the ability to dynamically establish a secret key joint to two nodes. Elliptic Curve Cryptography (ECC) has emerged as a suitable public key cryptographic foundation for WSN. This letter describes an efficient ECCbased method for self-certified key generation in resourceconstrained sensor nodes. A novel load-balancing technique yields reduced overall communications and facilitate an efficient distribution of the computational effort involved