19,432 research outputs found
Cryptanalysis of a threshold proxy signature with known signers
A scheme of threshold proxy signature with known signers was proposed by Hwang et al. In their scheme, the receiver can identify the proxy signers that actually generated a proxy signature. Tzeng et al. demonstrated that this signature scheme is insecure and proposed an improvement to mend the information leakage. This paper shows that the improved scheme is still insecure under the original signerĀ”Ā¦s forgery attack
Quantum e-commerce: A comparative study of possible protocols for online shopping and other tasks related to e-commerce
A set of quantum protocols for online shopping is proposed and analyzed to
establish that it is possible to perform secure online shopping using different
types of quantum resources. Specifically, a single photon based, a Bell state
based and two 3-qubit entangled state based quantum online shopping schemes are
proposed. The Bell state based scheme, being a completely orthogonal state
based protocol, is fundamentally different from the earlier proposed schemes
which were based on conjugate coding. One of the 3-qubit entangled state based
scheme is build on the principle of entanglement swapping which enables us to
accomplish the task without transmission of the message encoded qubits through
the channel. Possible ways of generalizing the entangled state based schemes
proposed here to the schemes which use multiqubit entangled states is also
discussed. Further, all the proposed protocols are shown to be free from the
limitations of the recently proposed protocol of Huang et al. (Quantum Inf.
Process. 14, 2211-2225, 2015) which allows the buyer (Alice) to change her
order at a later time (after initially placing the order and getting it
authenticated by the controller). The proposed schemes are also compared with
the existing schemes using qubit efficiency.Comment: It's shown that quantum e-commerce is not a difficult task, and it
can be done in various way
Identity-based edge computing anonymous authentication protocol
With the development of sensor technology and wireless communication technology, edge computing has a wider range of applications. The privacy protection of edge computing is of great significance. In the edge computing system, in order to ensure the credibility of the source of terminal data, mobile edge computing (MEC) needs to verify the signature of the terminal node on the data. During the signature process, the computing power of edge devices such as wireless terminals can easily become the bottleneck of system performance. Therefore, it is very necessary to improve efficiency through computational offloading. Therefore, this paper proposes an identity-based edge computing anonymous authentication protocol. The protocol realizes mutual authentication and obtains a shared key by encrypting the mutual information. The encryption algorithm is implemented through a thresholded identity-based proxy ring signature. When a large number of terminals offload computing, MEC can set the priority of offloading tasks according to the userās identity and permissions, thereby improving offloading efficiency. Security analysis shows that the scheme can guarantee the anonymity and unforgeability of signatures. The probability of a malicious node forging a signature is equivalent to cracking the discrete logarithm puzzle. According to the efficiency analysis, in the case of MEC offloading, the computational complexity is significantly reduced, the computing power of edge devices is liberated, and the signature efficiency is improved
Public Key Encryption Supporting Plaintext Equality Test and User-Specified Authorization
In this paper we investigate a category of public key encryption schemes which supports plaintext equality test and user-specified authorization. With this new primitive, two users, who possess their own public/private key pairs, can issue token(s) to a proxy to authorize it to perform plaintext equality test from their ciphertexts. We provide a formal formulation for this primitive, and present a construction with provable security in our security model. To mitigate the risks against the semi-trusted proxies, we enhance the proposed cryptosystem by integrating the concept of computational client puzzles. As a showcase, we construct a secure personal health record application based on this primitive
- ā¦