New and Improved Constructions of Nonmalleable Cryptographic Protocols

New constructions of cryptographic pseudorandom functions

New cryptographic constructions using generalized LWE

We present first a generalized LWE problem, which is essentially to extend the original LWE to the case of matrices. Then we use this new version of LWE problem, which we call matrix LWE problem to build new cryptographic schemes, which include a new key distribution scheme, a new key exchanges scheme and a new simple identity-based encryption scheme.

On Tolerant Cryptographic Constructions

We investigate how to construct secure cryptographic schemes, from few candidate schemes, some of which may be insecure. Namely, tolerant constructions tolerate the insecurity of some of the component schemes used in the construction. We define tolerant constructions, and investigate `folklore`, practical cascade and parallel constructions. We prove cascade of encryption schemes provide toleran...

LEGO and Other Cryptographic Constructions

Provably Secure Cryptographic Constructions

Modern cryptography has virtually no provably secure constructions. Starting from the first Diffie–Hellman key agreement protocol (Diffie & Hellman, 1976) and the first public key cryptosystemRSA (Rivest et al., 1978), not a single public key cryptographic protocol has been proven secure. Note, however, that there exist secure secret key protocols, e.g., the one-time pad scheme (Shannon, 1949; ...