This paper presents a flavor of OT named Independent Oblivious Transfer in the Public-Key Public-Randomness Model (PKPR IOT, in short), with respect to the open problem given by De Santis. First it gives a non-interactive implementation of IOT, which can independently and obliviously transfer polynomial messages. The implementation is based on Quadratic Residuosity Assumption. Since it is limited to pre-fixed times, then another non-interactive implementation of IOT is presented, which can independently transfer messages for any times. The second implementation requires the sender to be honest and the receiver couldn’t make his choice independently. So, the third interactive implementation is given. It is based on the BBCS oblivious transfer scheme of Rivest, and is rather more efficient than the above two non-interactive counterparts. All the three implementations presented are secure against receivers with unlimited computational power.
This paper presents a flavor of OT named Independent Oblivious Transfer in the Public-Key Public-Randomness Model (PKPR IOT, in short), with respect to the open problem given by De Santis. First it gives a non-interactive implementation of IOT, which can independently and obliviously transfer polynomial messages. The implementation is based on Quadratic Residuosity Assumption. Since it is limited to pre-fixed times, then another non-interactive implementation of IOT is presented, which can independently transfer messages for any times. The second implementation requires the sender to be honest and the receiver couldn’t make his choice independently. So, the third interactive implementation is given. It is based on the BBCS oblivious transfer scheme of Rivest, and is rather more efficient than the above two non-interactive counterparts. All the three implementations presented are secure against receivers with unlimited computational power.
In this work we investigate the power of Public Randomness in the context of Public-key cryptosystems. We consider the Diffie-Hellman Public-key model in which an additional short random string is shared by all users. This, which we call Public-Key Public-Randomness (PKPR) model, is very powerful as we show that it supports simple non-interactive implementations of important cryptographic primitives.We give the first completely non-interactive implementation of Oblivious Transfer. Our implementation is also secure against receivers with unlimited computational power.We propose the first implementation of non-interactive nature for Perfect Zero-Knowledge in the dual model of Brassard, Crepeau, and Chaum for all NP-languages.
Oblivious Transfer (OT) is a fundamental cryptographic primitive enabling privacy-preserving computation and constitutes a core building block for secure multi-party computation while supporting a wide range of security-sensitive applications: private information retrieval, zero-knowledge proofs, and password-authenticated key exchange, to cite a few. While recent advances in OT extension have significantly reduced amortised costs, their reliance on batches of random base OTs and substantial pre-computation phases limits their practicality in scenarios where the number of transfers is modest or where communication latency and client-side computation are critical constraints. In such settings, efficient base OT protocols remain both relevant and necessary. In this work, we introduce I-(OT)2, a novel base 1-out-of-2 OT protocol grounded in the quadratic residuosity problem, specifically designed to minimise receiver-side computation and interaction. Our construction is particularly appealing on client--server architectures in which the receiver operates on low-power hardware, such as Internet of Things (IoT) devices. Through a lightweight offline pre-computation phase, I-(OT)2 shifts the on-transfer computational burden almost entirely to the Sender, while reducing online communication to only six messages and four digests exchanged. We provide a detailed description of the protocol, accompanied by a formal proof of its security. Moreover, to demonstrate the viability of I-(OT)2, we also present an open-source proof-of-concept implementation (in C language) evaluated on real IoT hardware. Results are staggering: for 128-bit security using a 3072-bit RSA modulus, the receiver incurs an average online cost per OT as low as 2.80 μs on desktop platforms and 39.90 μs on IoT devices, more than 10× faster than the well known SimplestOT.
In an adaptive oblivious transfer (OT) protocol, a sender commits to a database of messages and then repeatedly interacts with a receiver in such a way that the receiver obtains one message per interaction of his choice (and nothing more) while the sender learns nothing about any of the choices. Recently, there has been significant effort to design practical adaptive OT schemes and to use these protocols as a building block for larger database applications. To be well suited for these applications, the underlying OT protocol should: (1) support an efficient initialization phase where one commitment can support an arbitrary number of receivers who are guaranteed of having the same view of the database, (2) execute transfers in time independent of the size of the database, and (3) satisfy a strong notion of security under a simple assumption in the standard model. We present the first adaptive OT protocol simultaneously satisfying these requirements. The sole complexity assumption required is that given (g, g a, g b, g c, Q), where g generates a bilinear group of prime order p and a, b, c are selected randomly from Zp, it is hard to decide if Q = g abc. All prior protocols in the standard model either do not meet our efficiency requirements or
Two novel constructions of one out of n oblivious transfer protocols from bilinear maps between groups are proposed. The protocols satisfy the category of non-interactive, mean that any sender S can obliviously transfer some secret(s) to a receiver R, but R does not send any messages back to S. The choice of a receiver is unconditionally secure. A sender's secrecy is guaranteed if the receiver is semi-honest in a standard model since the decision bilinear Diffie-Hellman problem is hard and the sender's secrecy is achieved when the receiver is a malicious party in a random oracle model since the bilinear Diffie-Hellman problem assumption holds. When a sender is a cheating party, the receiver will detect him/her and halt the protocol. A precise proof of the security of the protocols is presented.
Oblivious transfer, first introduced by Rabin, is one of the basic building blocks of cryp-tographic protocols. In an oblivious transfer (or more exactly, in its 1-out-of-2 variant), one party known as the sender has a pair of messages and the other party known as the receiver obtains one of them. Somewhat paradoxically, the receiver obtains exactly one of the messages (and learns nothing of the other), and the sender does not know which of the messages the receiver obtained. Due to its importance as a building block for secure protocols, the efficiency of oblivious transfer protocols has been extensively studied. However, to date, there are almost no known oblivious transfer protocols that are secure in the presence of malicious adversaries under the real/ideal model simulation paradigm (without using general zero-knowledge proofs). Thus, efficient protocols that reach this level of security are of great interest. In this paper we present efficient oblivious transfer protocols that are secure according to the ideal/real model simulation paradigm. We achieve constructions under the DDH, Nth residuosity and quadratic residuosity assumptions, as well as under the assumption that homomorphic encryption exists. 1
Assuming post-quantum one-way functions, we construct device-independent (DI) oblivious transfer (OT) and bit commitment: honest parties use only trusted classical computation to operate untrusted quantum devices, which may share arbitrary entanglement and behave non-IID. Security is simulation-based against quantum polynomial-time adversaries and composes sequentially with efficient simulators. One protocol skeleton serves both, in two regimes. With isolated laboratories and coordinate-local measurements in the honest receiver's device, it tolerates a constant rate of honest-device faults. With polylogarithmically many qubits of adaptive leakage between the laboratories and arbitrary joint measurements, it tolerates an inverse-polylogarithmic rate. Each elementary DI call uses a fresh, isolated batch of polylogarithmically many device coordinates, and total device use in the compiled OT protocol is polynomial. The commitment has efficient simulators against both parties and yields DI coin tossing with abort.
Because OT is complete for secure computation, the construction yields a DI protocol, with abort, for every efficiently computable classical functionality on a fixed number of parties, secure against static corruption of any proper subset of them.
The commitment's extractor changes a public parity relation through classical equivocation and leaves the device execution, hence its leakage, unchanged. A commit-and-prove functionality, disjoint audits, and an affine consistency check link the certified correlations to ideal OT. Sender security rests on a selector-aware parallel-repetition bound for the Magic Square game, which we derive from the two-round threshold theorem of Kundu and Tan.