On the basis of the modified four-coherent-state post-selection quantum key distribution protocol (Namiki and Hirano 2006 Preprint quant-ph/0608144v1), two 1-out-of-2 quantum oblivious transfer (QOT 1 2 ) protocols are proposed.The first proposed protocol (called the receiver-based QOT 1 2 protocol) requires the coherent states to be prepared by the receiver, whereas the second protocol (called the sender-based QOT 1 2 protocol) allows the coherent states to be generated by the sender.The main advantages of the proposed protocols are that (i) no quantum bit commitment schemes and the assumption of quantum memory are needed; (ii) less communication cost between participants is required, i.e. the receiver-based QOT 1 2 protocol requires only one quantum communication and one classical communication and the sender-based QOT 12 protocol requires only one quantum communication between participants during protocol execution; and (iii) the utilization of quantum states is very efficient, wherein the receiver-based and the sender-based QOT 1 2 protocols use only two coherent pulses and one coherent pulse respectively for sending the sender's two messages.
On the basis of the modified four-coherent-state post-selection quantum key distribution protocol (Namiki and Hirano 2006 Preprint quant-ph/0608144v1), two 1-out-of-2 quantum oblivious transfer (QOT 1 2 ) protocols are proposed.The first proposed protocol (called the receiver-based QOT 1 2 protocol) requires the coherent states to be prepared by the receiver, whereas the second protocol (called the sender-based QOT 1 2 protocol) allows the coherent states to be generated by the sender.The main advantages of the proposed protocols are that (i) no quantum bit commitment schemes and the assumption of quantum memory are needed; (ii) less communication cost between participants is required, i.e. the receiver-based QOT 1 2 protocol requires only one quantum communication and one classical communication and the sender-based QOT 12 protocol requires only one quantum communication between participants during protocol execution; and (iii) the utilization of quantum states is very efficient, wherein the receiver-based and the sender-based QOT 1 2 protocols use only two coherent pulses and one coherent pulse respectively for sending the sender's two messages.
In cryptography, oblivious transfer (OT) is an important multi-party cryptographic primitive and protocol, that is suitable for many upper-layer applications, such as secure computation, remote coin-flipping, electrical contract signing and exchanging secrets simultaneously. However, some no-go theorems have been established, indicating that one-out-of-two quantum oblivious transfer (QOT) protocols with unconditional security are impossible. Fortunately, some one-out-of-two QOT protocols using the concept of Crépeau’s reduction have been demonstrated not to conform to Lo’s no-go theorem, but these protocols require more quantum resources to generate classical keys using all-or-nothing QOT to construct one-out-of-two QOT. This paper proposes a novel and efficient one-out-of-two QOT which uses quantum resources directly instead of wasting unnecessary resources to generate classical keys. The proposed protocol is not covered by Lo’s no-go theorem, and it is able to check the sender’s loyalty and avoid the attack from the receiver. Moreover, the entangled state of the proposed protocol is reusable, so it can provide more services for the participants when necessary. Compared with other QOT protocols, the proposed protocol is more secure, efficient, and flexible, which not only can prevent external and internal attacks, but also reduce the required resources and resource distribution time.
This research proposes the first one-out-of-two quantum oblivious transfer (QOT) scheme that does not have a two-level structure and is not subject to Lo's no-go theorem. Instead, the proposed scheme is a simple and efficient approach based on nonorthogonal states. The nonorthogonality causes one of a pair of messages to be unable to be measured to achieve the irreversible goal of discarding a message, resulting in a one-out-of-two selection effect. The proposed QOT protocol is therefore built directly on quantum resources rather than on a two-level structure in which two classical keys must first be created using quantum resources (all-or-nothing QOT) and then a one-out-of-two protocol is built from there. Furthermore, the proposed protocol allows Alice and Bob to test each other's loyalty by comparing measurement results. In addition, the relationship with the no-go theorem is discussed in detail; this relationship is often overlooked in other studies. A security analysis demonstrates that the proposed protocol is secure against both external and internal attacks. In addition, an efficiency analysis shows that the proposed protocol is more efficient than other, two-level-structured protocols.
We propose a quantum protocol for 1-out-of-2, 1-out-of-n and k-out-of-n oblivious transfer. Oblivious transfer is a counter-intuitive cryptographic primitive in which the receiver receives only the information he is authorized for, while the sender does not know what information receiver received. In 1-out-of-2 oblivious transfer, Alice sends two bits to Bob who can choose only one of them to read, while Alice does not know which bit Bob read. k-out-of-n oblivious transfer is an extension of this idea. The proposed protocols do not require any classical communication, are practical, secure and can be implemented using current technology.
This paper proposes a cryptographic quantum communication scheme analogous to one out of two oblivious transfers based on quantum conjugate coding defined in a four-dimensional Hilbert space. The quantum uncertainty principle ensures that our scheme can satisfy the following two conditions: (i) a sender, Bob, can encode two bits of information $X\ensuremath{\in}{0,1}$ and $Y\ensuremath{\in}{0,1},$ but a receiver, Alice, can only obtain either X or Y dependent on her choice; and (ii) honest Bob, who attempts to encode (X,Y), cannot reveal Alice's choice. By contrast, when malicious Bob tries to reveal her choice, honest Alice can detect malicious Bob with a finite probability. Moreover, by using our proposed scheme many times, we can construct a protocol for quantum bit commitment (QBC) from Alice to Bob. Contrary to common belief, the security of our QBC protocol may not be violated by the well-known no-go theorem of QBC. This is because our QBC protocol does not meet the assumptions in which the no-go theorem holds.
Abstract Quantum oblivious transfer (QOT) is an essential cryptographic primitive, but unconditionally secure QOT is known to be impossible. Here, we propose a practical QOT protocol which is perfectly secure against dishonest senders without relying on any technological assumptions. It is also secure against dishonest receivers in the absence of long-term quantum memory and complicated collective measurements. The protocol is extremely feasible, as it can be implemented using currently available Mach–Zehnder interferometers, and no quantum memory, collective measurements, or entanglement are needed for honest participants. More importantly, compared with other practical QOT schemes, our protocol has an unbeatable efficiency since it requires the transmission of a single photon only.
Quantum cryptography is the field of cryptography that explores the quantum properties of matter. Generally, it aims to develop primitives beyond the reach of classical cryptography and to improve existing classical implementations. Although much of the work in this field covers quantum key distribution (QKD), there have been some crucial steps towards the understanding and development of quantum oblivious transfer (QOT). One can show the similarity between the application structure of both QKD and QOT primitives. Just as QKD protocols allow quantum-safe communication, QOT protocols allow quantum-safe computation. However, the conditions under which QOT is fully quantum-safe have been subject to intense scrutiny and study. In this review article, we survey the work developed around the concept of oblivious transfer within theoretical quantum cryptography. We focus on some proposed protocols and their security requirements. We review the impossibility results that daunt this primitive and discuss several quantum security models under which it is possible to prove QOT security.