Deniable Attribute Based Encryption for Branching Programs from LWE

Adaptively Secure Identity-Based Encryption from Lattices with Asymptotically Shorter Public Parameters

In this paper, we present two new adaptively secure identity-based encryption (IBE) schemes from lattices. The size of the public parameters, ciphertexts, and private keys are Õ(nκ), Õ(n), and Õ(n) respectively. Here, n is the security parameter, κ is the length of the identity, and d ∈ N is a flexible constant that can be set arbitrary (but will affect the reduction cost). Ignoring the poly-lo...

Riding on Asymmetry: Efficient ABE for Branching Programs

In an Attribute-Based Encryption (ABE) scheme the ciphertext encrypting a message μ, is associated with a public attribute vector x and a secret key skP is associated with a predicate P . The decryption returns μ if and only if P (x) = 1. ABE provides efficient and simple mechanism for data sharing supporting fine-grained access control. Moreover, it is used as a critical component in construct...

Bi-Deniable Inner Product Encryption from LWE

Deniable encryption (Canetti et al. CRYPTO ’97) is an intriguing primitive that provides a security guarantee against not only eavesdropping attacks as required by semantic security, but also stronger coercion attacks performed after the fact. The concept of deniability has later demonstrated useful and powerful in many other contexts, such as leakage resilience, adaptive security of protocols,...

Attribute-Based Encryption for Finite Automata from LWE

Constraint-Hiding Constrained PRFs for NC1 from LWE

Constraint-hiding constrained PRFs (CHCPRFs), initially studied by Boneh, Lewi and Wu [PKC 2017], are constrained PRFs where the constrained key hides the description of the constraint. Envisioned with powerful applications such as searchable encryption, private-detectable watermarking and symmetric deniable encryption, the only known candidates of CHCPRFs are based on indistinguishability obfu...