Oblivious Transfer(OT) protocol is an important primitive for designing cryptographic protocols.Designing OT protocol from bilinear pairing not only extends the bilinear pairing application but also increases the design technique of OT,which has important practical significance.This paper utilizes bilinear pairing to design a k-out-of-n OT protocol.The new protocol can protect both receiver’s privacy and sender’s privacy.The new protocol also can resist impersonation attacks,replay attacks and man-in-the-middle attacks.It can be used in an insecure channel,and the protocol has high efficiency.
Oblivious Transfer(OT) protocol is an important primitive for designing cryptographic protocols.Designing OT protocol from bilinear pairing not only extends the bilinear pairing application but also increases the design technique of OT,which has important practical significance.This paper utilizes bilinear pairing to design a k-out-of-n OT protocol.The new protocol can protect both receiver’s privacy and sender’s privacy.The new protocol also can resist impersonation attacks,replay attacks and man-in-the-middle attacks.It can be used in an insecure channel,and the protocol has high efficiency.
Oblivious transfer (OT) protocols mainly contain three categories: 1-out-of-2 OT, 1-out-of-nOT, andk-out-of-nOT. In most cases, they are treated as cryptographic primitives and are usually executed without consideration of possible attacks that might frequently occur in an open network, such as an impersonation, replaying, or man-in-the-middle attack. Therefore, when used in certain applications, such as mental poker games and fair contract signings, some extra mechanisms must be combined to ensure the security of the protocol. However, after a combination, we found that very few of the resulting schemes are efficient enough in terms of communicational cost, which is a significant concern for generic commercial transactions. Therefore, we propose a novelk-out-of-noblivious transfer protocol based on bilinear pairing, which not only satisfies the requirements of ak-out-of-nOT protocol, but also provides mutual authentication to resist malicious attacks. Meanwhile, it is efficient in terms of communication cost.
As traditional oblivious transfer protocols are treated as a cryptographic primitive, they are usually executed without the consideration of possible attacks, e.g., impersonation, replaying, and man-in-the-middle attacks. Therefore, when these protocols are applied in certain applications such as mental poker playing, some necessary mechanism must be executed first to ensure the security of subsequent communications. But doing this way, we found that almost all of the resulting mechanisms are not efficient enough in communicational cost which is a significant concern for commercial transactions. Inspired by these observations, we propose a novel secure oblivious transfer protocol based on bilinear pairing which not only can provide mutual authentication to resist malicious attacks but also is efficient in communicational cost, other than its original functions. Keywords: oblivious transfer, mutual authentication, ID-based cryptosystem, bilinear
Oblivious transfer (OT) protocol is a fundamental building block of cryptography and can be applied widely in many fields. A secure oblivious transfer protocol is supposed to ensure the privacy of both senders and receivers. The privacy of receivers means that the information being selected by receivers would never be revealed to senders. On the other hand, the privacy of senders means that receivers have no further information except for the one that has been selected. In this case, senders are able to deceive receivers by sending same messages. Likewise, in existing 1-out-of-n OT protocols, malicious senders can make all the n messages the same, so that receivers will always get the specific one assigned by senders. This indicates that privacy of receivers wouldnt work under the 1-out-of-n OT protocol. To prevent this kind of attack, this paper provides a general framework on how to design a secure OT protocol based on commutative and ciphertext equality test and take RSA as an example to explain how the protocol is processed.
Oblivious transfer (OT) protocol is an essential tool in cryptography that provides a wide range of applications such as secure multi-party computation, private information retrieval, private set intersection, contract signing, and privacy-preserving location-based services. The OT protocol has different variants such as one-out-of-2, one-out-of- n , k -out-of- n , and OT extension. In the OT (one-out-of-2, one-out-of- n , and OT extension) protocol, the sender has a set of messages, whereas the receiver has a key. The receiver sends that key to the sender in a secure way; the sender cannot get any information about the received key. The sender encrypts every message by operating on every message using the received key and sends all the encrypted messages to the receiver. The receiver is able to extract only the required message using his key. However, in the k -out-of- n OT protocol, the receiver sends a set of k keys to the sender, and in replay, the sender sends all the encrypted messages. The receiver uses his keys and extracts the required messages, but it cannot gain any information about the messages that it has not requested. Generally, the OT protocol requires high communication and computation cost if we transfer millions of oblivious messages. The OT extension protocol provides a solution for this, where the receiver transfers a set of keys to the sender by executing a few numbers of OT protocols. Then, the sender encrypts all the messages using cheap symmetric key cryptography with the help of a received set of keys and transfers millions of oblivious messages to the receiver. In this work, we present different variants of OT protocols such as one-out-of-2, one-out-of- n , k -out-of- n , and OT extension. Furthermore, we cover various aspects of theoretical security guarantees such as semi-honest and malicious adversaries, universally composable, used techniques, computation, and communication efficiency aspects. From the analysis, we found that the semi-honest adversary-based OT protocols required low communication and computation costs as compared to malicious adversary-based OT protocols.
The Oblivious Transfer (OT), introduced by Rabin in 1981, has become an important and fundamental cryptography technique. An OT protocol should have two important characteristics: sender's privacy and chooser's privacy. The sender is a party who will deliver a secret to chooser. The chooser is another party who acts as receiver to learn some information about input from sender. The chooser learns of certain information concerning sender's input while sender is not allowed to know what chooser has learned. Moreover, chooser cannot acquire any messages that he/she did not choose. Naor and Pinkas have recently proposed an efficient oblivious transfer protocol (EOT) that implementes 1-out-of-n protocol, but this EOT has a flaw: it cannot withstand the same message attack. In this paper, we will improve Naor and Pinkas EOT and make it resistant to the same message attack.
Due to the rapid development of internet in our daily life, protecting privacy has become a focus of attention. To create privacy-preserving database and prevent illegal user access the database, oblivious transfer with access control (OTAC) was proposed, which is a cryptographic primitive that extends from oblivious transfer (OT). It allows a user to anonymously query a database where each message is protected by an access control policy and only if the user' s attribute satisfy that access control policy can obtain it. In this paper, we propose a new protocol for OTAC by using elliptic curve cryptography, which is more efficient compared to the existing similar protocols. In our scheme, we also preserves user's anonymity and ensures that the user's attribute is not disclosed to the sender. Additionally, our construction guarantees the user to verify the correctness of messages recovered at the end of each transfer phase.