Identity-Based Lossy Encryption from Learning with Errors

Obtaining Efficient Fully Simulatable Oblivious Transfer from General Assumptions

We introduce a general construction of fully simulatable oblivious transfer based on lossy encryption. Furthermore, we extend the common definition of lossy encryption by introducing the notion of computationally lossy encryption. If the cryptosystem used is computationally lossy, our general construction yields oblivious transfer protocols with computational security for both parties. Otherwis...

Identity Based Encryption from Learning With Errors

Improvement on a Fuzzy Identity-based Encryption Scheme

Sahai and Waters introduced a fuzzy id-based encryption (FIBE) scheme in which an identity was viewed as a set of descriptive attributes, and any user with a private key for an identity ID was allowed to decrypt a ciphertext encrypted with an identity ID′ , if and only if the identity ID and ID′were close to each other as measured by the “set overlap” distance metric. After that, Shweta Agrawal...

Compact Lossy and All-but-One Trapdoor Functions from Lattice

Lossy trapdoor functions (LTDF) and all-but-one trapdoor functions (ABO-TDF) are fundamental cryptographic primitives. And given the recent advances in quantum computing, it would be much desirable to develop new and improved lattice-based LTDF and ABO-TDF. In this work, we provide more compact constructions of LTDF and ABO-TDF based on the learning with errors (LWE) problem. In addition, our L...

Compact Identity Based Encryption from LWE

We construct an identity-based encryption (IBE) scheme from the standard Learning with Errors (LWE) assumption that has compact public-key and achieves adaptive security in the standard model. In particular, our scheme only needs 2 public matrices to support O(log λ)-bit length identity, and O(λ/ log λ) public matrices to support λ-bit length identity. This improves over previous IBE schemes fr...