Due to little attention given to anonymous protection against eavesdropping attacks in Bitcoin network, this paper initiatively proposes a solution to Bitcoin anonymization based on network structure. We first present a general adversarial network model for formulizing deanonymization attack, then present a novel propagation method APRP(Adaptive PageRank Propagation) that adopts PageRank as propagation delay factor and constantly adjusts PR-value of nodes to adapt to network dynamics. Experiments on both simulated and real Bitcoin networks confirm the superiority of APRP in terms of 20-50% performance enhancement under various deanonymization attacks.
Open access
Internet Traffic Analysis and Secure E-voting
Privacy-Preserving Technologies in Data
Advanced Steganography and Watermarking Techniques
Eugenia Politou, Fran Casino, Efthimios Alepis, Constantinos Patsakis
Abstract—Blockchain’s evolution during the past decade is astonishing: from bitcoin to over 2.000 altcoins, and from decentralised electronic payments to transactions programmable by smart contracts and complex tokens governed bydecentralised organisations. While the new generation of blockchain appli- cations is still evolving, blockchain’s technical characteristics are also advancing. Yet, immutability, a hitherto indisputable property according to which blockchain data cannot be edited nor deleted, remains the cornerstone of blockchain’s security. Nevertheless, blockchain’s immutability is being called into ques- tion lately in the light of the new erasing requirements imposed by the GDPR’s “Right to be Forgotten (RtbF)” provision. As the RtbF obliges blockchain data to be editable in order restricted content redactions, modifications or deletions to be applied when requested, blockchains compliance with the regulation is indeed challenging, if not impracticable. Towards resolving this contradiction, various methods and techniques for mutable blockchains have been proposed in an effort to satisfy regulatory erasing requirements while preserving blockchains’ security. To this end, this work aims to provide a comprehensive review on the state-of-the-art research approaches, technical workarounds and advanced cryptographic techniques that have been put forward to resolve this conflict and to discuss their potentials, constraints and limitations when applied in the wild to either permissioned or permissionless blockchains. Index Terms—Blockchain, immutability, Right to be forgotten, GDPR
A video record plays a crucial role in providing evidence for crime scenes or road accidents. However, the main problem with the video record is that it is often vulnerable to various video tampering attacks. Although visual evidence is required to conduct an integrity verification before investigations, it is still difficult for human vision to detect a forgery. In this paper, we propose a novel video integrity verification method (IVM) that takes advantage of a blockchain framework. The proposed method employs an effective blockchain model in centralized video data, by combining a hash-based message authentication code and elliptic curve cryptography to verify the integrity of a video. In our method, video content with a predetermined size (segments) is key-hashed in a real-time manner and stored in a chronologically chained fashion, thus establishing an irrefutable database. The verification process applies the same procedure to the video segment and generates a hash value that can be compared with the hash in the blockchain. The proposed IVM is implemented on a PC environment, as well as on an accident data recorder-embedded system for verification. The experimental results show that the proposed method has better detection capabilities and robustness toward various kinds of tampering, such as copy–move, insert, and delete, as compared to other state-of-the-art methods. An analysis based on execution time along with an increase in the number of blocks within the blockchain shows a minimal overhead in the proposed method.
Advanced Steganography and Watermarking Techniques
Bo Zhao, Liming Fang, Hanyi Zhang, Chunpeng Ge · 7 authors
With the development of information technology, films, music, and other publications are inclined to be distributed in digitalized form. However, the low cost of data replication and dissemination leads to digital rights problems and brings huge economic losses. Up to now, existing digital rights management (DRM) schemes have been powerless to deter attempts of infringing digital rights and recover losses of copyright holders. This paper presents a YODA-based digital watermark management system (Y-DWMS), adopting non-repudiation of smart contract and blockchain, to implement a DRM mechanism to infinitely amplify the cost of infringement and recover losses copyright holders suffered once the infringement is reported. We adopt game analysis to prove that in Y-DWMS, the decision of non-infringement always dominates rational users, so as to fundamentally eradicate the infringement of digital rights, which current mainstream DRM schemes cannot reach.
Open access
Advanced Steganography and Watermarking Techniques
The signing of electronic contracts and the certification of important documents are realized by utilizing blockchain, identity-based cryptography and electronic signature technology. Blockchain technology can realize the data distributed ledgers through the entire system nodes, the whole processes, and the entire transactions. Identity-based cryptography and electronic signature technology can achieve data integrity, privacy, and nonrepudiation. All data is shared by all participating nodes, the information in the cyberspace is more transparent, and the behavior is more traceable. A complete and compliant contract signing process and data certification is achieved.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Mehmet Aydar, Salih Cemil Cetin, Serkan Ayvaz, Betul Aygun
The disruptive technology of blockchain can deliver secure solutions without the need for a central authority. In blockchain protocols, assets that belong to a participant are controlled through the private key of an asymmetric key pair that is owned by the participant. Although, this lets blockchain network participants to have sovereignty on their assets, it comes with the responsibility of managing their own keys. Currently, there exists two major bottlenecks in managing keys; $a)$ users don't have an efficient and secure way to store their keys, $b)$ no efficient recovery mechanism exists in case the keys are lost. In this study, we propose secure methods to efficiently store and recover keys. For the first, we introduce an efficient encryption mechanism to securely encrypt and decrypt the private key using the owner's biometric signature. For the later, we introduce an efficient recovery mechanism using biometrics and secret sharing scheme. By applying the proposed key encryption and recovery mechanism, asset owners are able to securely store their keys on their devices and recover the keys in case they are lost.
Levi Dolan, Bethany Kavanaugh, Kevin Korinek, Brittney Sandler
Blockchain technology allows data to be effectively organized, stored, and shared. Its unique decentralized authentication system means no central database exists to store information. All information is shared by a network of nodes and is continuously updated. Blockchain is currently being used across several industries due to its unique features: tamper-proof records, authenticity, transparency, and elimination of third-party brokers. These features offer potential for applications in libraries, archives, and museums as well.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
While significant advancements have been made in the field of multimedia forensics to detect altered content, existing techniques mostly focus on enabling the content recipient to verify the content integrity without any inputs from the content creator. In many application scenarios, the creator has a strong incentive to establish the provenance and integrity of the multimedia data created and released by him. Hence, there is a strong need for mechanisms that allow the content creator to prove the authenticity of the released content. Since blockchain technology provides an immutable distributed database, it is an ideal solution for reliably time-stamping content with its creation time and storing an irrefutable signature of the content at the time of its creation. However, a simple digital signature scheme does not allow modification of the content after the initial commitment. Authorized multimedia content alteration by its creator is often necessary (e.g., redaction of faces to protect the privacy of individuals in a video, redaction of sensitive fields in a text document) before the content is distributed. The main contributions of this paper are: (i) a novel sanitizable signature scheme that enables the content creator to prove the integrity of the redacted content, while preventing the recipients from reconstructing the redacted segments based on the published commitment, and (ii) a blockchain-based solution for securely managing the sanitizable signature. The proposed solution employs a robust hashing scheme using chameleon hash function and Merkle tree to generate the initial signature, which is stored on the blockchain. The auxiliary data required for the integrity verification step is retained by the content creator and only a signature of this auxiliary data is stored on the blockchain. Any modifications to the multimedia content requires only updating the signature of the auxiliary data, which is securely recorded on the blockchain. We demonstrate that the proposed approach enables verification of integrity of redacted multimedia content without compromising the content privacy requirements.
Digital Media Forensic Detection
Advanced Steganography and Watermarking Techniques
In this paper, we consider a scenario where a bitcoin liquidity provider sells bitcoins to clients. When a client pays for a bitcoin online, the provider is able to link the client's payment information to the bitcoin sold to that client. To address the privacy concerns of clients, we require that the bitcoin provider cannot tell the relationship between the real identities of clients and the sold bitcoins in the blockchain. This requirement can be effectively achieved by using blind signatures. However, existing blind signature schemes are incompatible with the Elliptic Curve Digital Signature Algorithm (ECDSA) which is used by most of the existing bitcoin protocol, thus cannot be applied directly in Bitcoin. In this paper, we propose a new blind signature scheme that allows generating a blind signature compatible with the standard ECDSA. Afterwards, we make use of the new scheme to achieve bitcoin transaction anonymity. The new scheme is built on a variant of the Paillier cryptosystem and its homomorphic properties. As long as the modified Paillier cryptosystem is semantically secure, the new blind signature scheme has blindness and unforgeability.
Open access
Blockchain Technology Applications and Security
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
With the proliferation of the Internet of Things (IoTs), their devices have been collecting our personal data to enhance our life styles and their purposes. Care must be taken when handling such sensitive data to protect the data owners' privacy while guaranteeing the integrity when the data is accessed by a third party. Furthermore, data should be available without much delay to support medical emergencies. Unfortunately, IoT devices may be limited with storage and computational resources to operate highly secure operations and respond to data requests. In this paper, we propose SSP, a novel mechanism that protects the privacy and integrity of the data collected by IoT devices without having a single point of failure, while minimizing the cryptographic operations that must be performed on IoT devices. SSP utilizes the blockchain data structure for availability and integrity, and Multi-Party-Computations (MPC) for privacy protection. We implemented SSP in C/C++ and according to our evaluation results, SSP is efficient in computation, communication, and storage operations on IoT devices.
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
Blockchain provides a decentralized trade means, which has attracted both academic and industrial researchers' attention. It was first proposed as the basic structure of bitcoin. In practice, it could be hacked for gaining profit or performing some illegal transactions, hence, a question about how to detect these potential risks has been raised. This paper builds a model for blockchain core protocol, and adopts the trace semantics, i.e. a sequence of actions, which can record any possible conditions that the running protocol may reach. Also, as an application of DDoS attack on blockchain, triangle attack is shown and can be formalized and detected by the contradiction to the security property. Furthermore, some advice to defend the triangle attack are presented.
User Authentication and Security Systems
Advanced Steganography and Watermarking Techniques
In our previous study, we found three requirements for digital watermarking. The first is that to prevent watermark information of an image from being diverted to other images, this information must be generated based on the original image. The second is that after the original image is modified/edited, it should still be able to be used the same as the original image. The third is that multiple digital watermarks should be stored and managed without relying on trusted third parties. To meet these requirements, we proposed a digital-copyright-management system based on perceptual hashing and blockchain. However, because we used conventional perceptual hashing in that study, we could not draw sufficient conclusions about the first and second requirements. In this current study, to obtain a stable message digest, we propose a method of improving perceptual hashing based on machine learning. With this method, an image is first modified/edited using various methods to generate an image set. This image set is then input into a convolutional neural network (CNN) to calculate the features of the images, and the data of the CNN intermediate layer are output as machine learning data. Finally, through machine learning, latent stochastic variables are determined that can be used to calculate latent image features, and the perceptual hash value of this image set is calculated using these image features for the blockchain and digital watermarking. The method also records these latent stochastic variables on the blockchain to ensure copyright security by ensuring that these variables cannot be used by those other than the original author.
Advanced Steganography and Watermarking Techniques
Abstract A major line of research on blockchains is geared towards enhancing the privacy of transactions through anonymity using generic non-interactive proofs. However, there is a good cluster of application scenarios where complete anonymity is not desirable and accountability is in fact required. In this work, we utilize non-interactive proofs of knowledge of elliptic curve discrete logarithms to present membership and verifiable encryption proof, which offers plausible anonymity when combined with the regular signing process of the blockchain transactions. The proof system requires no trusted setup, both its communication and computation complexities are linear in the number of set members, and its security relies on the discrete logarithm assumption. As a use-case for this scenario, we present Mesh which is a blockchain-based framework for supply chain management using RFIDs. Finally, the confidentiality of the transacted information is realized using a lightweight key chaining mechanism implemented on RFIDs. We formally define and prove the main security features of the protocol, and report on experiments for evaluating the performance of the modified transactions for this system.
Open access
Cryptography and Data Security
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
In the era of the Internet of Things(loT) smart devices are connected with wire or wireless way. The IoT devices are capable of sensing the environment and has the ability to transmit that information to the next level. The application area of IoT is Smart city, Smart transportation, Healthcare sector, Agriculture, Monitoring environment. Each of these applications, lots of information are share or transmit among different devices. In the information sharing system among devices, lots of security and privacy challenges exist like data leakage, data modification, device identity. In this paper, authors firstly identify the communication protocols used in IoT application and given their working principle. Secondly, challenges exist in IoT and corresponding Blockchain solution approach are explained, Lastly, the authors proposed a secure architecture based on open Blockchain which can solve some of the challenges in IoT applications.
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
In this work, we add secure multiparty computation capabilities to the permissioned blockchain architecture of Hyperledger Fabric, and use them to implement the clearing price mechanism for initial public offering (IPO). As with any blockchain, the core property in Fabric is that all peers must see the same ledger, so using confidential data on the ledger is a challenge. To address this challenge we use cryptographic secure multiparty computation (MPC), which requires that we integrate a few new mechanisms into the Fabric architecture. Specifically we need to let the peers access local information such as their respective secret keys, and also send messages to each other while executing smart contracts. We also had to add to Fabric a library that implements the required cryptographic tools, and to make that library accessible from the smart contracts. We demonstrated the effectiveness of this solution by using it to implement the clearing price mechanism for IPOs. We designed an efficient cryptographic protocol for the IPO clearing price mechanism, and used our integrated system to run it on Fabric. Although not fully optimized yet, the performance of the resulting implementation is more than fast enough for this particular application, ranging from 8 to 23 seconds to execute an IPO sale.
Blockchain Technology Applications and Security
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
Recently, Blockchain a decentralized as well as distributed public ledger technology in (P2P) peer-to-peer network, has received considerable attention. It applies a block structure (linked) used to store as well as verify data and also applies the trusted mechanism for synchronization of changes in data in order to possibly create a tamper-proof digital platform for sharing as well as storing data. Blockchain can also be used to diverse the interactive system of internet (e.g. supply chain system, Internet of things). The blockchain model of bitcoin has been used in wide range of services like from asset trading to transaction of real estate, from services of escrow to national income distribution system in some countries. In this paper we present a comprehensive survey on blockchain, working of blockchain, security analysis on blockchain, privacy threats for blockchain and potential applications of blockchain.
Blockchain Technology Applications and Security
IoT and Edge/Fog Computing
Advanced Steganography and Watermarking Techniques
Witnessing the increasingly pervasive deployment of security video surveillance systems(VSS), more and more individuals have become concerned with the issues of privacy violations. While the majority of the public have a favorable view of surveillance in terms of crime deterrence, individuals do not accept the invasive monitoring of their private life. To date, however, there is not a lightweight and secure privacy-preserving solution for video surveillance systems. The recent success of blockchain (BC) technologies and their applications in the Internet of Things (IoT) shed a light on this challenging issue. In this paper, we propose a Lightweight, Blockchain-based Privacy protection (Lib-Pri) scheme for surveillance cameras at the edge. It enables the VSS to perform surveillance without compromising the privacy of people captured in the videos. The Lib-Pri system transforms the deployed VSS into a system that functions as a federated blockchain network capable of carrying out integrity checking, blurring keys management, feature sharing, and video access sanctioning. The policy-based enforcement of privacy measures is carried out at the edge devices for real-time video analytics without cluttering the network.
Open access
3 source records
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Blockchain has recently emerged as an important tool that can enable critical distributed applications without requiring centralized trust. For example, public blockchains have been used to enable many different cryptocurrencies. Unfortunately, existing public blockchains and smart contracts deployed on them may disclose sensitive information. Although there is some ongoing work that leverage advanced cryptography to address some of these sensitive information leakage issues, they require significant changes to existing and popular blockchains such as Ethereum and are usually computationally expensive. On the other hand, private blockchains have been proposed to allow more efficient and privacy-preserving data sharing among pre-approved group of nodes/participants. Although private blockchains address some of the privacy challenges by allowing sensitive data to be only seen by the select group of participants, they do not allow public accountability of transactions since transactions are approved by known set of users, and cannot be accessed publicly. Given these observations, one natural question that arise is, can we leverage both public and private blockchain infrastructures to enable efficient, privacy enhancing and accountable applications? In this work, we try to address this challenge in the context of digital auctions. Mainly, we propose a novel hybrid blockchain architecture that combines private and public blockchains to allow sensitive bids to be opened on a private blockchain so that only the auctioneer can learn the bids, and no one else. At the same time, we leverage public blockchains to make the auction winner announcement, and payments accountable. Furthermore, using smart contracts deployed on public blockchain, we show how to incentivize truthful behavior among the auction participants. Our extensive empirical results show that this architecture is more efficient in terms of run time and monetary cost compared to pure public blockchain based auction implementations.
2 source records
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Ziyuan Wang, Lin Yang, Qin Wang, Donghai Liu · 6 authors
Blockchain is an emerging technology that has the potential to revolutionize the global industry and create a trusted relationship in a multi-party business network. There are a number of practical use cases where blockchain has been applied. One specific area is the Art industry, where it is a natural fit in the way that art forensics and transactions are conducted, tracked and recorded. This motivates us to develop the ArtChain platform to assist the Art Industry. In this paper, we present ArtChain, which is an integrated trading system based on blockchain. It includes the front end, the back end, the services, the smart contract, the chain connection and the deployment scripts from the bottom to the top. To the best of our knowledge, this is the first deployed blockchain-enabled art trading platform in Australia. It provides a transparent yet privacy-preserving, and tamper-proof transaction history for registration, provenance, and traceability of art assets. Our objective analysis and evaluation show that the ArtChain platform is applicable and practical. For the interest of other researchers, our system implementation related resources are open-sourced on Github.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Online voting is an alternative to age old paper ballot system and the currently popular electronic voting machines (EVM). An electronic voting portal should offer security and integrity along with the transparency of votes and privacy of voters. This paper proposes an e-voting system based on blockchain that eliminates some of the limitations in existing voting systems. The paper also presents state of art of some blockchain frameworks for e-voting. The presented implementation is suitable for small scale elections like inside corporate houses, board rooms etc. The implementation uses smart contract from Ethereum. Truffle framework is used in this paper for development, testing and deploying smart contracts. Ganache is used as Ethereum client for testing. Here Meta-mask is used as browser wallet.
Internet Traffic Analysis and Secure E-voting
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Saulo dos Santos, Chukwuka Chukwuocha, Shahin Kamali, Ruppa K. Thulasiram
Cryptocurrencies like Bitcoin use the blockchain technology to record transactions in a distributed and secure way. Each block contains a cryptographic hash of the previous block in addition to a set of transactions that it records. The first step for a miner to add a new block to the blockchain is to select a set of pending transactions from a mempool. The total size of selected transactions should not exceed the fixed capacity of blocks. If a miner completes the computationally-hard task of finding the cryptographic hash of the formed block, the block can be added to the blockchain in which case the transactions in that block will become complete. Transaction might have a fee that is granted to the miner upon being complete. As such, when forming a new block, miners tend to select transactions that offer the best fees. Finding a set of transactions with maximum total fee that fit into a block translates to the classic knapsack problem, which is an NP-hard problem. Meanwhile, miners are in fierce competition for mining blocks and hence cannot dedicate too much computational power for selecting the best set of transactions. Most existing solutions to tackle this problem are based on sorting the set of pending transactions by the ratio between their fee and their size. While the sorting step is not a bottleneck in normal situations, transaction can grow explosively in case of a market turbulence like that of 2017. Meanwhile, the total number of transactions increases over time. As such, it is desirable to have an efficient strategy that does not rely on sorting transactions before forming a block. In this paper, we review some of the existing strategies for miners to select transactions from the mempool. We also introduce a robust solution called Size-Density Table (SDT) for selecting transactions that does not use sorting. We perform a theoretical and experimental analysis of our solutions to compare it with other strategies. Our results indicate that our algorithm runs faster than previous approaches while the quality of its solutions (the total fees collected in its blocks) is also slightly better than the best existing strategies.
Blockchain Technology Applications and Security
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
Konstantin Zhidanov, Sergey Bezzateev, Alexandra Afanasyeva, Mikhail Sayfullin · 7 authors
The blockchain technology is currently penetrating different sides of modern ICT community. Most of the devices involved in blockchain-related processes are specially designed targeting only the mining aspect. At the same time, the use of wearable and mobile devices may also become a part of blockchain operation, especially during the charging time. The paper considers the possibility of using a large number of constrained devices supporting the operation of the blockchain. The utilization of such devices is expected to improve the efficiency of the system and also to attract a more substantial number of users. Authors propose a novel consensus algorithm based on a combination of Proof-of-Work (PoW), Proof-of-Activity (PoA), and Proof-of-Stake (PoS). The paper first overviews the existing strategies and further describes the developed cryptographic primitives used to build a blockchain involving mobile devices. A brief numerical evaluation of the designed system is also provided in the paper.
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques