Deniable ring authentication protocol allows a sender to deny an authentication and his identity is anonymous to the receiver. In this work,we propose a new deniable ring authentication protocol based on the multi-receiver encryption scheme. The receiver encrypts an authentication key with multi-receiver encryption scheme and sends it to the sender. The sender decrypts it using his private key to obtain the authentication key and uses this key to authenticate messages. This protocol only requires two communication rounds and its deniability holds in the concurrent setting without requiring timing assumption due to the multi-receiver encryption.
Deniable ring authentication protocol allows a sender to deny an authentication and his identity is anonymous to the receiver. In this work,we propose a new deniable ring authentication protocol based on the multi-receiver encryption scheme. The receiver encrypts an authentication key with multi-receiver encryption scheme and sends it to the sender. The sender decrypts it using his private key to obtain the authentication key and uses this key to authenticate messages. This protocol only requires two communication rounds and its deniability holds in the concurrent setting without requiring timing assumption due to the multi-receiver encryption.
The notion of deniable authentication protocol was introduced in 1998 by Dwork et al. [11] and Aumann and Rabin [1, 2] independently. As a new cryptographic authentication protocol, a deniable authentication protocol enables an intended receiver to identify the source of a given message without being able to prove the identity of the sender to a third party. Over the past years, many deniable authentication protocols have been proposed. In this paper, we would like to present a universal encrypted deniable authentication protocol from any public key encryption scheme. Provided that the public key encryption scheme is secure, a secure deniable authentication protocol can be directly derived.
In a multi-receiver encryption system, a sender chooses a set of authorized receivers and sends them a message securely and efficiently, as the message is well encrypted and only one ciphertext corresponding to the message is generated no matter how many receivers the sender has chosen. It can be applied to video conferencing systems, pay-per-view channels, remote education, and so forth. Due to privacy considerations, an authorized receiver may not expect that his identity is revealed. In 2010, anonymous multi-receiver identity-based (ID-based) encryption was first discussed, and furthermore, many works on the topic have been presented so far. Unfortunately, we find that all of those schemes fail to prove the chosen ciphertext attacks (CCA) security in either confidentiality or anonymity. In this manuscript, we propose the first anonymous multi-receiver ID-based authenticated encryption scheme with CCA security in both confidentiality and anonymity. In the proposed scheme, the identity of the sender of a ciphertext can be authenticated by the receivers after a successful decryption. In addition, the proposed scheme also is the first CCA-secure one against insider attacks. Moreover, only one pairing computation is required in decryption.
Intended receiver and deniability properties are two basic properties satisfied by deniable authentication protocols. Recently, a deniable authentication protocol with sender protection is proposed to protect the right of the real sender. In other words, the sender can prove that he/she really sent the message to guard against circumvention by some receivers. However, the honest receiver still suffers the circumventing risk due to the senders' deniability. If the sender sent a deniable authenticated message to the innocent receiver and claimed that the message was generated by receivers. Then the receiver has nothing to convince the others that he/she is innocent. To provide fair protection and anonymity both for senders and receivers, a new deniable authentication protocol with anonymous fair protection is proposed.
Deniable Authentication protocols allow a Sender to authenticate a message for a Receiver, in a way that the Receiver cannot convince a third party that such authentication (or any authentication) ever took place.We present two new approaches to the problem of deniable authentication. The novelty of our schemes is that they do not require the use of CCA-secure encryption (all previous known solutions did), thus showing a different generic approach to the problem of deniable authentication. This new approach is practically relevant as it leads to more efficient protocols and security reductions.In the process we point out a subtle definitional issue for deniability. In particular we propose the notion of forward deniability, which requires that the authentications remain deniable even if the Sender wants to later prove that she authenticated a message. We show that forward deniability is not implied by the original notion of deniability, by showing some deniable protocols which are not forward deniable. Our new proposals are forward deniable.
In this paper, we extend the work by M. Naor [7] on deniable ring authentication to include key establishment. Two secure deniable private key establishment protocols will be proposed. These two related schemes create only a secure private channel between Alice and Bob where the identity of Bob remains completely hidden. The first scheme does not require Alice to been within the user set S and in fact does not even require Alice to have a public-private key pair. The second scheme requires that Alice choose a user set S such that she is also within set S. This scheme also indirectly requires that Alice have a public-private key pair. Similar to the deniable ring authentication protocol by Naor, the protocols proposed here only assumes the existence of strong public key encryption schemes where all members have already established public and private keys. Finally, the problem of ciphertext search and ciphertext ambiguity will also be examined and a solution will be proposed.
A deniable authentication protocol should satisfy the property that only the intended receiver authenticates the sender’s identity of received messages. This property is called authentication property. On the other hand, the intended receiver cannot prove the sender’s identity to the third party. The second property is called deniability property. To satisfy deniability property, in most deniable authentication protocols, the receiver is able to forge/modify the received message from the sender. Since the received data is forgeable by the receiver, the sender easily denies that he/she sent the data. Although the sent message is deniable for the sender, the sender still has no evidence to prove that he/she sent the message to prevent the receiver’s circumvention. In this propose, a new property, sender protection, is proposed for the deniable authentication protocol. In a deniable authentication protocol with sender protection, although the sent message is still forgeable by the receiver, the sender can provide an evidence to prove that whether or not the message is really sent from him/her. To protect senders more completely, it is better that the sender is anonymous in a deniable authentication protocol. Therefore, another goal of our research is to design a deniable authentication protocols with anonymous and protected sender.