Voting is a complex process with a lot depending on it. Building an e-voting system that can guarantee anonymity, verifiability, and transparency together is a challenging task. Continuous efforts are being made to improve the voting system to achieve these properties. Recently, blockchain has hit the technology space with many promises, especially to make verifiable and transparent decentralized systems. However, a major challenge faced with blockchain-based e-voting systems is to achieve the users' anonymity while ensuring only authorized voters should be able to vote, and that too only once. To address these issues, this paper proposes a blockchain-based e-voting system with secret contracts. We have used Enigma (a secure multiparty computation platform) to design secret contracts. The proposed system meets most of the features required to conduct free and fair voting electronically.
Internet Traffic Analysis and Secure E-voting
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Steganography is a solution for covert communication and blockchain is a p2p network for data transmission, so the benefits of blockchain can be used in steganography. In this paper, we discuss the advantages of blockchain in steganography, which include the ability to embed hidden data without manual change in the original data, as well as the readiness of the blockchain platform for data transmission and storage, which eliminates the need for the Steganographer to design and implement a new platform for data transmission and storage. We have proposed two algorithms for steganography in blockchain, the first one is a high-capacity algorithm for the key and the steganography algorithm exchange and switching, and the second one is a medium-capacity algorithm for embedding hidden data. Also, by reviewing the previous three steganography schemes in blockchain, we have examined their drawback and have showed that none of them are practical schemes for steganography in blockchain. Then, we have explained the challenges of steganography in blockchain from the steganographers and steganalyzers point of view.
Open access
2 source records
cs.CR
Advanced Steganography and Watermarking Techniques
Group signature schemes play a vital role in protecting identity privacy of a member of a group who signs a message using the group signature. However, in the existing group signature schemes the centralized group manager has control over all the participants, and these managers can be malicious. They may take a biased decision when there is a dispute among the group members or while revealing the identity of a group member. To overcome the trust issues related to centralized group managers and to improve user privacy, a decentralized group signature scheme (DGSS) is proposed by decentralizing the role of the group manager. The proposed scheme will be more suitable for decentralized environments like a blockchain. Security analysis along with the proof of correctness is also provided for the proposed scheme. A framework for a blockchain-based e-auction protocol using the DGSS is also proposed in this paper.
Open access
Blockchain Technology Applications and Security
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
Covert channels are designed to protect the communication relationship of the sender and receiver. Traditional covert channels have become insecure due to the continuous improvement of traffic analysis techniques. In this context, there is an urgent need to identify new approaches for covert channels. Blockchain is an emerging technique with characteristics of user anonymity, a flooding propagation mechanism, and tamper resistance, which make it a compelling platform for covert channels. Previous approaches applied Bitcoin as the underlying blockchain, and its pseudoanonymity may expose the communication relationship. Moreover, the reliance of these approaches on prenegotiated labels to identify transactions containing covert messages further reduced their concealment. In this work, we present a practical and secure covert channel over Monero. Compared to Bitcoin, Monero's full anonymity efficiently protects the relationship between the sender and receiver. Moreover, no labels are employed to identify special transactions. The receiver filters and extracts the covert message using his private key. In this study, we make a complete assessment of the robustness, reliability, and anti-traceability of our protocol, as these properties are regarded as desirable for a covert channel. We also formalize the definition of security for covert channels through a transaction distinguishing experiment. A rigorous proof shows that our protocol meets this definition and is secure to use. Finally, we make a detailed comparison between our protocol and the existing blockchain-based covert channels.
Open access
Internet Traffic Analysis and Secure E-voting
Adversarial Robustness in Machine Learning
Advanced Steganography and Watermarking Techniques
Bitcoin transactions rely on digital signatures to prove the ownership of bitcoin. The private signing key of the bitcoin owner is the key component to enable a bitcoin transaction. If the signing key of a bitcoin is stolen, the theft who possesses the key can make a transaction of the bitcoin. In this paper, based on the distance-based encryption (DBE), we propose an enhanced version of bitcoin in order to protect the signing key. Our approach is based on our two-factor authentication, where the signing key cannot be retrieved without being identified via the password and biometric authentication scheme, and the user is only required to enter his password and fingerprint (or other biometric information such as a factual image) to retrieve the key. By doing this, we can effectively improve the bitcoin security and provide stronger authentication. An attractive feature of our scheme is that one of encryption schemes is asymmetric, in the sense that the decryption key (biometric information) is not stored in the device. We also provide the security model and proof to justify the security of our scheme.
Open access
2 source records
Blockchain Technology Applications and Security
User Authentication and Security Systems
Advanced Steganography and Watermarking Techniques