This paper presents efficient structure-preserving signature schemes based on simple
assumptions such as decisional linear. We first give two general frameworks for constructing …

A modular approach to constructing cryptographic protocols leads to simple designs but
often inefficient instantiations. On the other hand, ad hoc constructions may yield efficient …

Abstract Structure-preserving cryptography is a world where messages, signatures,
ciphertexts and public keys are entirely made of elements of a group over which a bilinear …

Adaptive oblivious transfer (OT) is a protocol where a sender initially commits to a database
{M_i\} _ i= 1^ NM ii= 1 N. Then, a receiver can query the sender up to k times with private …

We propose two constructions of oblivious transfer with access control (OTAC), ie, oblivious
transfer schemes in which a receiver can obtain a message only if her attributes, which are …

Adaptive oblivious transfer (OT) is a protocol where a sender initially commits to a database
{M i} i= 1 N. Then, a receiver can query the sender up to k times with private indexes ρ 1 …

An oblivious transfer with access control protocol (OTAC) allows us to protect privacy of
accesses to a database while enforcing access control policies. Existing OTAC have several …

In today's Internet world, security, privacy and efficiency are three prime concerns in
designing any cryptographic protocol. Adaptive oblivious transfer with access policy (AOT …

Databases often require the flexibility to control which entities can access specific database
records. Such access control is absent in works that provide private access to databases …

We define an ideal functionality F _ UD and a construction Π _ UD for an updatable
database (UD). UD is a two-party protocol between an updater and a reader. The updater …