Verifiably Encrypted Signatures Without Random Oracles

Verifiably encrypted signatures are employed when a signer wants to sign a message for a verifier but does not want the verifier to possess his signature on the message until some certain requirements of his are satisfied. This paper presented new verifiably encrypted signatures from bilinear pairings. The proposed signatures share the properties of simplicity and efficiency with existing verifiably encrypted signature schemes. To support the proposed scheme, it also exhibited security proofs that do not use random oracle assumption. For existential unforgeability, there exist tight security reductions from the proposed verifiably encrypted signature scheme to a strong but reasonable computational assumption.

Key substitution attacks on some verifiably encrypted signature schemes

As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ＇ s scheme, Gorantla, et al. ＇ s scheme and Ming, et al. ＇ s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.

A chaos-based quantum group signature scheme in quantum cryptosystem

A quantum group signature(QGS) scheme is proposed on the basis of an improved quantum chaotic encryption algorithm using the quantum one-time pad with a chaotic operation string. It involves a small-scale quantum computation network in three phases, i.e. initializing phase, signing phase and verifying phase. In the scheme, a member of the group signs the message on behalf of the group while the receiver verifies the signature's validity with the aid of the trusty group manager who plays a crucial role when a possible dispute arises. Analysis result shows that the signature can neither be forged nor disavowed by any malicious attackers.

Neural Cryptography with Fog Computing Network for Health Monitoring Using IoMT

Sleep apnea syndrome(SAS)is a breathing disorder while a person is asleep.The traditional method for examining SAS is Polysomnography(PSG).The standard procedure of PSG requires complete overnight observation in a laboratory.PSG typically provides accurate results,but it is expensive and time consuming.However,for people with Sleep apnea(SA),available beds and laboratories are limited.Resultantly,it may produce inaccurate diagnosis.Thus,this paper proposes the Internet of Medical Things(IoMT)framework with a machine learning concept of fully connected neural network(FCNN)with k-near-est neighbor(k-NN)classifier.This paper describes smart monitoring of a patient’s sleeping habit and diagnosis of SA using FCNN-KNN+average square error(ASE).For diagnosing SA,the Oxygen saturation(SpO2)sensor device is popularly used for monitoring the heart rate and blood oxygen level.This diagnosis information is securely stored in the IoMT fog computing network.Doctors can care-fully monitor the SA patient remotely on the basis of sensor values,which are efficiently stored in the fog computing network.The proposed technique takes less than 0.2 s with an accuracy of 95%,which is higher than existing models.

AES RSA-SM2 Algorithm against Man-in-the-Middle Attack in IEC 60870-5-104 Protocol

The IEC60870-5-104 protocol lacks an integrated authentication mechanism during plaintext transmission, and is vulnerable to security threats, monitoring, tampering, or cutting off communication connections. In order to verify the security problems of 104 protocol, the 104 master-slave communication implemented DoS attacks, ARP spoofing and Ettercap packet filtering and other man-in-the-middle attacks. DoS attacks may damage the network functions of the 104 communication host, resulting in communication interruption. ARP spoofing damaged the data privacy of the 104 protocol, and Ettercap packet filtering cut off the communication connection between the master and the slave. In order to resist the man-in-the-middle attack, the AES and RSA hybrid encryption signature algorithm and the national secret SM2 elliptic curve algorithm are proposed. AES and RSA hybrid encryption increases the security strength of communication data and realizes identity authentication. The digital signature implemented by the SM2 algorithm can realize identity verification, ensure that the data has not been tampered with, and can ensure the integrity of the data. Both of them improve the communication security of the 104 protocol.

Arbitrated quantum signature scheme based on reusable key

An arbitrated quantum signature scheme without using entangled states is proposed.In the scheme,by employing a classical hash function and random numbers,the secret keys of signer and receiver can be reused.It is shown that the proposed scheme is secure against several well-known attacks.Specifically,it can stand against the receiver’s disavowal attack.Moreover,compared with previous relevant arbitrated quantum signature schemes,the scheme proposed has the advantage of less transmission complexity.