Countermeasures for Collusion Attacks Exploiting Host Signal Redundancy

2005 ◽  
pp. 216-230 ◽  
Author(s):  
Gwenaël Doërr ◽  
Jean-Luc Dugelay
Keyword(s):  
Collusion Attacks ◽  
Host Signal

scholarly journals Proof-of-Prestige: A Useful Work Reward System for Unverifiable Tasks

2021 ◽  
Vol 21 (2) ◽  
pp. 1-27
Author(s):  
Michał Król ◽  
Alberto Sonnino ◽  
Mustafa Al-Bassam ◽  
Argyrios G. Tasiopoulos ◽  
Etienne Rivière ◽  
...  
Keyword(s):  
Mobile Application ◽  
Reward System ◽  
Fair Exchange ◽  
Content Dissemination ◽  
Collusion Attacks ◽  
Computational Overhead ◽  
Smart Contract ◽  
Memory Footprint ◽  
Vast Range ◽  
Over Time

As cryptographic tokens and altcoins are increasingly being built to serve as utility tokens, the notion of useful work consensus protocols is becoming ever more important. With useful work consensus protocols, users get rewards after they have carried out some specific tasks useful for the network. While in some cases the proof of some utility or service can be provided, the majority of tasks are impossible to verify reliably. To deal with such cases, we design “Proof-of-Prestige” (PoP)—a reward system that can run directly on Proof-of-Stake (PoS) blockchains or as a smart contract on top of Proof-of-Work (PoW) blockchains. PoP introduces “prestige,” which is a volatile resource that, in contrast to coins, regenerates over time. Prestige can be gained by performing useful work, spent when benefiting from services, and directly translates to users minting power. Our scheme allows us to reliably reward decentralized workers while keeping the system free for the end-users. PoP is resistant against Sybil and collusion attacks and can be used with a vast range of unverifiable tasks. We build a simulator to assess the cryptoeconomic behavior of the system and deploy a full prototype of a content dissemination platform rewarding its participants. We implement the blockchain component on both Ethereum (PoW) and Cosmos (PoS), provide a mobile application, and connect it with our scheme with a negligible memory footprint. Finally, we adapt a fair exchange protocol allowing us to atomically exchange files for rewards also in scenarios where not all the parties have Internet connectivity. Our evaluation shows that even for large Ethereum traces, PoP introduces sub-millisecond computational overhead for miners in Cosmos and less than 0.013$ smart contract invocation cost for users in Ethereum.

scholarly journals An Active and Passive Reputation Method for Secure Wideband Spectrum Sensing Based on Blockchain

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1346
Author(s):  
Xinyu Xie ◽  
Zhuhua Hu ◽  
Min Chen ◽  
Yaochi Zhao ◽  
Yong Bai
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Cooperative Spectrum Sensing ◽  
Sampling Rate ◽  
Radio Networks ◽  
Single Node ◽  
Decision Algorithm ◽  
Collusion Attacks ◽  
Wideband Spectrum Sensing

Spectrum is a kind of non-reproducible scarce strategic resource. A secure wideband spectrum sensing technology provides the possibility for the next generation of ultra-dense, ultra-large-capacity communications to realize the shared utilization of spectrum resources. However, for the open collaborative sensing in cognitive radio networks, the collusion attacks of malicious users greatly affect the accuracy of the sensing results and the security of the entire network. To address this problem, this paper proposes a weighted fusion decision algorithm by using the blockchain technology. The proposed algorithm divides the single-node reputation into active reputation and passive reputation. Through the proposed token threshold concept, the active reputation is set to increase the malicious cost of the node; the passive reputation of the node is determined according to the historical data and recent performance of the blockchain. The final node weight is obtained by considering both kinds of reputation. The proposed scheme can build a trust-free platform for the cognitive radio collaborative networks. Compared with the traditional equal-gain combination algorithm and the centralized sensing algorithm based on the beta reputation system, the simulation results show that the proposed algorithm can obtain reliable sensing results with a lower number of assistants and sampling rate, and can effectively resist malicious users’ collusion attacks. Therefore, the security and the accuracy of cooperative spectrum sensing can be significantly improved in cognitive radio networks.

scholarly journals Secure Encapsulation Schemes Using Key Recovery System in IoMT Environments

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3474
Author(s):  
Taehoon Kim ◽  
Wonbin Kim ◽  
Daehee Seo ◽  
Imyeong Lee
Keyword(s):  
Internet Of Things ◽  
Diagnosis And Treatment ◽  
Key Recovery ◽  
Collusion Attacks ◽  
Malicious User ◽  
Systems Security ◽  
Recovery System ◽  
Multi Agent ◽  
Internet Of Medical Things ◽  
Gain Access

Recently, as Internet of Things systems have been introduced to facilitate diagnosis and treatment in healthcare and medical environments, there are many issues concerning threats to these systems’ security. For instance, if a key used for encryption is lost or corrupted, then ciphertexts produced with this key cannot be decrypted any more. Hence, this paper presents two schemes for key recovery systems that can recover the lost or the corrupted keys of an Internet of Medical Things. In our proposal, when the key used for the ciphertext is needed, this key is obtained from a Key Recovery Field present in the cyphertext. Thus, the recovered key will allow decrypting the ciphertext. However, there are threats to this proposal, including the case of the Key Recovery Field being forged or altered by a malicious user and the possibility of collusion among participating entities (Medical Institution, Key Recovery Auditor, and Key Recovery Center) which can interpret the Key Recovery Field and abuse their authority to gain access to the data. To prevent these threats, two schemes are proposed. The first one enhances the security of a multi-agent key recovery system by providing the Key Recovery Field with efficient integrity and non-repudiation functions, and the second one provides a proxy re-encryption function resistant to collusion attacks against the key recovery system.

scholarly journals Protection of Visual Data Transmission for Vessel Traffic Systems Using Joint Fingerprinting and Decryption Method Based on Modified Hill Cipher

2012 ◽  
Vol 19 (2) ◽  
pp. 5-17
Author(s):  
Bartosz Czaplewski ◽  
Krzysztof Czaplewski
Keyword(s):  
Data Transmission ◽  
Video On Demand ◽  
Multimedia Data ◽  
Visual Data ◽  
Collusion Attack ◽  
Collusion Attacks ◽  
Traffic Systems ◽  
Industrial Cameras ◽  
High Level ◽  
Fingerprinting Methods

Abstract Vessel traffic systems provide a high level of safety on coastal waters due to coastal radar stations and industrial cameras transmitting information to traffic supervision centers, as well. To improve a vessel traffic services is very important to ensure the speed and secrecy for the transmission of video images. The paper presents the basic issues of the multimedia data protection by digital watermarking and fingerprinting methods. Main applications for such digital marking were described in the paper as well as its requirements. Furthermore, the importance of multicast transmission for fingerprinting methods was presented by comparing the scalability of methods using only unicast transmissions and methods using multicast transmissions. The paper also presents the greatest threat to fingerprinting methods, which are attacks performed by more than one pirate. These attacks are called collusion attacks. The criteria that should be followed during identifying rogue users taking part in the collusion attack on the security systems has been presented. The paper also contains description of the extended Hillcast method, which belongs to the group of JFD (Joint Fingerprinting and Decryption) methods. The method provides a cryptographic security and digital fingerprinting of multimedia content, while maintaining high scalability. Main purpose of this method is VoD (Video on Demand) service, but it can also be used in vessel traffic supervision systems, such as VTS and AIS. In the last part of paper, there are results of studies which indicate high resistance to most common collusion attacks. Method proposed by authors can enhance the security of visual data transmission in vessel traffic systems.

scholarly journals TheC. difficile clnRABoperon initiates adaptations to the host environment in response to LL-37

2018 ◽  
Author(s):  
Emily C. Woods ◽  
Adrianne N. Edwards ◽  
Shonna M. McBride
Keyword(s):  
Gene Expression ◽  
Diarrheal Disease ◽  
Regulatory System ◽  
Innate Immune ◽  
Cellular Transport ◽  
Intestinal Environment ◽  
Host Defense Peptide ◽  
Surface Active ◽  
Pleiotropic Regulator ◽  
Host Signal

ABSTRACTTo cause disease,Clostridioides(Clostridium)difficilemust resist killing by innate immune effectors in the intestine, including the host antimicrobial peptide, cathelicidin (LL-37). The mechanisms that enableC. difficileto adapt to the intestine in the presence of antimicrobial peptides are unknown. Expression analyses revealed an operon,CD630_16170-CD630_16190(clnRAB), which is highly induced by LL-37 and is not expressed in response to other cell-surface active antimicrobials. This operon encodes a predicted transcriptional regulator (clnR) and an ABC transporter system (clnAB), all of which are required for function. Analyses of aclnRmutant indicate that ClnR is a pleiotropic regulator that directly binds to LL-37 and controls expression of numerous genes, including many involved in metabolism, cellular transport, signaling, gene regulation, and pathogenesis. The data suggest that ClnRAB is a novel regulatory mechanism that senses LL-37 as a host signal and regulates gene expression to adapt to the host intestinal environment during infection.Author SummaryC. difficileis a major nosocomial pathogen that causes severe diarrheal disease. ThoughC. difficileis known to inhabit the human gastrointestinal tract, the mechanisms that allow this pathogen to adapt to the intestine and survive host defenses are not known. In this work, we investigated the response ofC. difficileto the host defense peptide, LL-37, to determine the mechanisms underlying host adaptation and survival. Expression analyses revealed a previously unknown locus, which we namedclnRAB, that is highly induced by LL-37 and acts as a global regulator of gene expression inC. difficile. Mutant analyses indicate that ClnRAB is a novel regulatory system that senses LL-37 as a host signal to regulate adaptation to the intestinal environment.

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