Decentralized cryptocurrency exchanges offer compelling security benefits over centralized exchanges: users control their funds and avoid the risk of an exchange hack or malicious operator. However, because user assets are fully accessible by a secret key, decentralized exchanges pose significant internal security risks for trading firms and automated trading systems, where a compromised system can result in total loss of funds. Centralized exchanges mitigate this risk through API key based security policies that allow professional users to give individual traders or automated systems specific…
The interplay between security and reliability is poorly understood. This paper shows how triple modular redundancy affects a side-channel attack (SCA). Our counterintuitive findings show that modular redundancy can increase SCA resiliency.
What kind of noise guarantees security for the Kirchhoff-Loop-Johnson-Noise key exchange?
本文是对我们最近一篇关于Kirchhoff-Law-Johnson-Noise(KLJN)安全密钥交换系统中噪声特性分析的补充[Gingl and Mingesz,PLOS ONE 9(2014)e96109,doi:10.1371/journal.pone.0096109]。在这里,我们使用纯粹的数学统计推导来证明,只有正态分布与特殊的缩放可以保证安全。我们的结果与早期的物理假设一致[Kish,Phys. Lett. A 352(2006)178 - 182,doi:10.1016/j.physleta.2005.11.062]。此外,我们已经进行了数值模拟表明,通信显然是不安全的噪声属性的选择不当。本文没有考虑使用时间和相关性分析来防止攻击。
Due to the widespread of advanced digital imaging devices, forgery of digital images became more serious attack patterns. In this attack scenario, the attacker tries to manipulate the digital image to conceal some meaningful information of the genuine image for malicious purposes. This leads to increase security interest about protecting images against integrity tampers. This paper proposes a novel technique for protecting colored images against forgery and pixel tamper. The proposed approach is designed as a hybrid model from three security techniques, Message Digest hashing algorithm (MD5), …
The Trusted Platform Module (TPM) version 2.0 provides a two-phase key exchange primitive which can be used to implement three widely-standardized authenticated key exchange protocols: the Full Unified Model, the Full MQV, and the SM2 key exchange protocols. However, vulnerabilities have been found in all of these protocols. Fortunately, it seems that the protections offered by TPM chips can mitigate these vulnerabilities. In this paper, we present a security model which captures TPM's protections on keys and protocols' computation environments and in which multiple protocols can be analyzed i…
In (Nature) Science Report 5 (2015) 13653, Vadai, Mingesz and Gingl (VMG) introduce a new Kirchhoff-law-Johnson-noise (KLJN) secure key exchanger that operates with 4 arbitrary resistors (instead of 2 arbitrary resistance values forming 2 identical resistor pairs in the original system). They state that in this new, VMG-KLJN, non-equilibrium system with nonzero power flow, the security during the exchange of the two (HL and LH) bit values is as strong as in the original KLJN scheme. Moreover, they claim that, at practical conditions, their VMG-KLJN protocol "supports more robust protection aga…
Currently, one of the most widely used protocols to secure cryptocurrency assets in centralized exchanges is categorizing wallets into cold and hot. While cold wallets hold user deposits, hot} wallets are responsible for addressing withdrawal requests. However, this method has some shortcomings such as: 1) availability of private keys in at least one cold device, and~2) exposure of all private keys to one trusted cold wallet admin. To overcome such issues, we design a new protocol for managing cold wallet assets by employing native multi-signature schemes. The proposed cold wallet system, invo…
The rapid development of IoT networks has led to a research trend in designing effective security features for them. Due to the power-constrained nature of IoT devices, the security features should remain as lightweight as possible. Currently, most of the IoT network traffic is unencrypted. The leakage of smart devices' unencrypted data can come with the significant cost of a privacy breach. To have a secure channel with encrypted traffic, two endpoints in a network have to authenticate each other and calculate a short-term key. They can then communicate through an authenticated and secure cha…
Akiyama et al. (Int. J. Math. Indust., 2019) proposed a post-quantum key exchange protocol that is based on the hardness of solving a system of multivariate non-linear polynomial equations but has a design strategy different from ordinary multivariate cryptography. Their protocol has two versions, an original one and a modified one, where the modified one has a trade-off that its security is strengthened while it has non-zero error probability in establishing a common key. In fact, the evaluation in their paper suggests that the probability of failing to establish a common key by the modified …
This paper introduces a new attack against the Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange scheme. The attack is based on the nonlinearity of the noise generators. We explore the effect of total distortion (TD) at the second order (D2), third order (D3), and a combination of the second and third orders (D2,3) on the security of the KLJN scheme. It is demonstrated that a as little as 1% results in a notable power flow along the information channel, which leads to a significant information leak. We also show that decreasing the effective temperature (that is, the wire voltage) and, in…
Threshold schemes exist for many cryptographic primitives like signatures, key derivation functions, and ciphers. At the same time, practical key exchange protocols based on Diffie-Hellman (DH) or ECDSA primitives are not designed or implemented in a threshold setting. In this paper, we implement popular key exchange protocols in a threshold manner and show that this approach can be used in practice. First, we introduce two basic threshold DH key agreement schemes that provide enhanced security features in comparison with the classic DH primitive: dealerless distributed key generation, thresho…
Quantum networks open the way to an unprecedented level of communication security. However, due to physical limitations on the distances of quantum links, current implementations of quantum networks are unavoidably equipped with trusted nodes. As a consequence, the quantum key distribution can be performed only on the links. Due to this, some new authentication and key exchange schemes must be considered to fully benefit from the unconditional security of links. One such approach uses Multiple Non-Overlapping Paths (MNOPs) for key exchange to mitigate the risk of an attack on a trusted node. T…
Can Cross-Layer Design Bridge Security and Efficiency? A Robust Authentication Framework for Healthcare Information Exchange Systems
Air Defense College, Military Academy(防空学院,军事学院);Faculty of Engineering, Ain Shams University(艾因夏姆斯大学工程学院);University of Essex(埃塞克斯大学);The Egyptian Technical Research and Development Center(埃及技术研发中心)