Message authentication is an interactive procedure that allows a legitimate sender Alice to send and authenticate a message M to a legitimate receiver Bob. To prevent the attacks from an adversary Eve, Alice and Bob usually share a secret key K. In this paper, we study a novel authentication framework as follows. Firstly, Alice sends a message M to Bob over a noiseless channel; Secondly, Alice generates an authentication tag with the message M and secret key K; Thirdly, Alice encodes the tag into a codeword Xn; Finally, Alice transmits the codeword Xn to Bob over a wiretap channel. This paper defines an authentication channel capacity under a fixed tag rate, and show that it equals to H(X|Z). Specifically, we prove that the authentication protocol proposed in Ref. [15] is capacity-achievable under our authentication model.
In this paper, a novel message authentication model using the same key over wiretap channel is proposed to achieveinformation-theoretic security. Specifically, in the proposed model, there is a discrete memoryless channelW1:X→Ybetween transmitter Alice and receiver Bob, while an attacker Oscar is connected with Alice via discrete memoryless channelW2:X→Z. Alice encodes messageMto codeword (S,Xn), using an encoding function with secret keyK. Then,Sis sent to Bob over a one-way noiseless channel (fully controlled by Oscar), andXnis sent over the wiretap channel, sayX→(Y,Z). Building on this model, a new message authentication scheme is proposed. The scheme incorporates a secure channel coding, which uses random coding techniques to detect man-in-the-middle (MITM) attacks. The authentication channel capacity is studied in a specific channel model whenW2is not less noisy thanW1. We theoretically demonstrate that the authentication channel capacity is much larger than the secrecy capacity, since Bob does not need to recover information transmitted over the noisy channel.
In this paper, we investigate multi-message authentication to combat adversaries with infinite computational capacity. An authentication framework over a wiretap channel
(W1,W2) is proposed to achieve information-theoretic security with the same key. The proposed framework bridges the two research areas in physical (PHY) layer security: secure transmission and message authentication. Specifically, the sender Alice first transmits message
M to the receiver Bob over
(W1,W2) with an error correction code; then Alice employs a hash function (i.e.,
ε-AWU
2 hash functions) to generate a message tag
S of message
M using key
K, and encodes
S to a codeword
Xn by leveraging an existing strongly secure channel coding with exponentially small (in code length
n) average probability of error; finally, Alice sends
Xn over
(W1,W2) to Bob who authenticates the received messages. We develop a theorem regarding the requirements/conditions for the authentication framework to be information-theoretic secure for authenticating a polynomial number of messages in terms of
n. Based on this theorem, we propose an authentication protocol that can guarantee the security requirements, and prove its authentication rate can approach infinity when
n goes to infinity. Furthermore, we design and implement an efficient and feasible authentication protocol over binary symmetric wiretap channel (BSWC) by using \emph{Linear Feedback Shifting Register} based (LFSR-based) hash functions and strong secure polar code. Through extensive experiments, it is demonstrated that the proposed protocol can achieve low time cost, high authentication rate, and low authentication error rate.
In this paper, we investigate multi-message authentication to combat adversaries with infinite computational capacity. An authentication framework over a wiretap channel (W_1, W_2) is proposed to achieve information-theoretic security with the same key. The proposed framework bridges the two research areas in physical (PHY) layer security: secure transmission and message authentication. Specifically, the sender Alice first transmits message M to the receiver Bob over (W_1, W_2) with an error correction code; then Alice employs a hash function (i.e., ε-AWU_2 hash functions) to generate a message tag S of message M using key K, and encodes S to a codeword X^n by leveraging an existing strongly secure channel coding with exponentially small (in code length n) average probability of error; finally, Alice sends X^n over (W_1, W_2) to Bob who authenticates the received messages. We develop a theorem regarding the requirements/conditions for the authentication framework to be information-theoretic secure for authenticating a polynomial number of messages. Based on this theorem, we propose and implement an efficient and feasible authentication protocol over binary symmetric wiretap channel (BSWC) by using Linear Feedback Shifting Register based (LFSR-based) hash functions and strong secure polar code. Through extensive experiments, it is demonstrated that the proposed protocol can achieve low time cost, high authentication rate, and low authentication error rate.
Security constraint results in rate-loss in wiretap channels. In this paper we propose a coding scheme for two user Multiple Access Channel with Wiretap (MAC-WT), where previous messages are used as a key to enhance the secrecy rates of both the users until we achieve the usual capacity region of a Multiple Access Channel (MAC) without the wiretapper (Shannon capacity region). With this scheme only the message that is being transmitted is proved to be secure with respect to all the information that the adversary (eavesdropper) possesses. In the second part of the paper we improve the security constraint such that not only the message being transmitted is secure but all the messages transmitted in the immediate past are secure w.r.t. all the information o f the eavesdropper. To achieve this goal we introduce secret key buffers at both the users, as well as at the legitimate receiver (Bob). Finally we consider a fading MAC-WT and show that with this coding/decoding scheme we can achieve the capacity region of a fading MAC (in ergodic sense).
An authentication protocol is a procedure by which a sender tries to convey n bits of information, which we call an input message, to a receiver. An adversary controls the network over which the sender and the receiver talk and may change any message before it reaches its destination. This paper deals with the simple scenario where two parties, Alice and Bob, communicate and want to assure that the message received by Bob is the one sent by Alice. Unconditional cryptographic security cannot be generated simply from scratch, but must be based on some given primitive to start with. In this paper, we introduce a message authentication protocol with unconditional cryptographic security. More precisely, we give protocols using a weakly secret key allowing for the exchange of authenticated messages.
We study a keyless authentication problem in a new noisy model, where there is a discrete memoryless channel (DMC) W1from sender Alice to receiver Bob and a DMC W2from adversary Oscar to Bob. In addition, there is an insecure noiseless channel between Alice and Bob. Under this model, we characterize the condition under which an authentication from Alice to Bob is possible. We also construct a secure authentication protocol that has an authentication rate approaching infinity. Finally, we prove that the authentication capacity of a noninteractive authentication over binary symmetric channels is exactly 1. This is an interesting result as Shannon capacity of channel W1is strictly less than 1 while the noiseless channel is completely unreliable.