Short Signatures from Diffie–Hellman: Realizing Almost Compact Public Key

Short Signatures From Diffie-Hellman: Realizing Short Public Key

In EUROCRYPT 2005, Waters [42] proposed a signature scheme based on the computational Diffie-Hellman (DH) assumption without random oracles. His scheme is the first and sole signature scheme in the category of (hash-and-sign) signature schemes secure under the DH assumption in the standard model and has also been applied to the design of numerous protocols in the various cryptographic areas. Ho...

Short Signatures with Short Public Keys from Homomorphic Trapdoor Functions

Short Signatures from Diffie-Hellman, Revisited: Sublinear Public Key, CMA Security, and Tighter Reduction

Designing efficient signature scheme based on the standard assumption such as the Computational Diffie-Hellman (CDH) assumption is important both from a practical and a theoretical point of view. Currently, there are only three standard model CDH-based signature schemes with short signatures due to Waters (EUROCRYPT 2005), and Seo and Böhl et al. (the merged paper in EUROCRYPT 2013). The Waters...

Compact Structure-Preserving Signatures with Almost Tight Security

In structure-preserving cryptography, every building block shares the same bilinear groups. These groups must be generated for a specific, a priori fixed security level, and thus it is vital that the security reduction of all involved building blocks is as tight as possible. In this work, we present the first generic construction of structure-preserving signature schemes whose reduction cost is...

Tightly Secure Signatures and Public-Key Encryption

We construct the first public-key encryption scheme whose chosen-ciphertext (i.e., IND-CCA) security can be proved under a standard assumption and does not degrade in either the number of users or the number of ciphertexts. In particular, our scheme can be safely deployed in settings in which no a-priori bound on the number of encryptions and/or users is known. As a central technical building b...