Signcryption design and analysis

Abstract

A signcryption algorithm also ensures both confidentiality and authenticity newlineof data being communicated over a public channel Zheng (1997). Most of newlinethe earlier version of signcryptions uses certificates that creates overhead. newlineAn identity-based signcryption uses the identity of a sender and a receiver newlineand the corresponding private key respectively. Signcryption based on the newlineidentity has gained much importance due to their simplicity and flexibility, newlineand their promising potential as a cryptographic platform. newlineIn the first phase, this thesis aims at designing identity-based signcryption with significantly low communication and computation cost, using bilinear pairings. The proposed one possesses two properties, namely, indistinguishable against chosen cipher attack and existential unforgeable against newlinechosen message attack respectively. In the proposed design, the sender newlinecomputes a pairing in advance during signcryption, that makes it more efficient at user-end. The first proposed IBSC design achieves security under newline modified bilinear Diffie-Hellman inversion and modified bilinear strong newlineDiffie-Hellman assumptions. The second proposed IBSC is proved secure newlineunder decision bilinear Diffie-Hellman and computation Diffie-Hellman newlineassumptions in the standard model. newline