Blockchain Papers

Geoffroy Couteau, Maryam Zarezadeh

No abstract is available for this record.

Lucas Deighton Chrisostomides

This paper uses CSSD developed by Two sets of cryptocurrencies were considered, one containing the 34 largest cryptocurrencies by market capitalisation and the other containing 15 cryptocurrencies with market capitalisations under $200 million. Any cryptocurrencies launched after 21/09/2018 were excluded from the samples in the interests of consistency. Using CSSD, no herding was detected while with CSAD a weak herding effect was observed, though the results were not statistically significant. This paper has important implications for cryptocurrency investors, researchers, and policymakers.

Yingying Li, Jianfeng Ma, Yinbin Miao, Ximeng Liu · 5 authors

No abstract is available for this record.

Gianluca Brian, Sebastian Faust, Elena Micheli, Daniele Venturi

No abstract is available for this record.

Liang Zhang, Feiyang Qiu, Feng Hao, Haibin Kan

Distributed key generation (DKG) is widely used in multi-party computation and decentralized applications. DKG has two phases, namely sharing and reconstruction. Most of the prior DKG protocols need at least 2 rounds for the sharing phase, in case some party raises a dispute. The existing 1-round DKG protocol [Fouqueet al., PKC’01], built based on a publicly verifiable secret sharing (PVSS) scheme, assumes a static adversary model and its reconstruction phase requires$O(n^{2})$communication complexity. Motivated by the observation that a ciphertext-policy attribute-based encryption (CP-ABE) scheme hides secret sharing (SS) in ciphertext, we utilize decentralized CP-ABE to achieve the first adaptively secure 1-round DKG protocol. Firstly, a CP-ABE scheme enables the ciphertexts in DKG to be externally decrypted, making our protocol superior to the PVSS-based DKG protocol in reconstruction. The communication and computation complexities are both lowered to$O(n)$thanks to the constant-sized decryption key and the proposed batch decryption. The use of CP-ABE also makes our DKG protocol storage-friendly, i.e., the parties store no ciphertext after the sharing phase. Secondly, we add non-interactive zero-knowledge (NIZK) proofs to make the CP-ABE ciphertext publicly verifiable by leveraging the sigma protocol and the Fiat-Shamir heuristic. Thirdly, we demonstrate our protocol’s feasibility by presenting a proof-of-concept implementation over Ethereum, which is used as a public channel and a trustworthy computation platform. The implementation is a non-trivial task due to Ethereum’s incompatibility with the bilinear mapping group.

Xiao Yang, Mengling Liu, Man Ho Au, Xiapu Luo · 5 authors

Verifiably encrypted signature (VES) allows a signer to encrypt a signature under the public key of a trusted third party (aka adjudicator) in a verifiable manner. Recently, Yanget al.proposed a practical verifiably encrypted signature scheme for ECDSA and initiated the study of escrow protocol for Bitcoin via VES. This paper generalizes and improves the VES scheme of Yanget al., such that it covers a family of signatures with similar structures, including ECDSA, Schnorr and their variants. Our construction is very efficient: comparing with Yanget al.’s construction, the size of the resulting VES (for ECDSA) is reduced by more than 25 times. The only caveat is that the adjudicator is required to store a look-up table of size around 270MB. Our scheme naturally gives rise to escrow protocols for mainstream cryptocurrencies that employ ECDSA-like signatures to authorise transaction, including Bitcoin, Ethereum, Cardano, Chainlink, etc.

Giuseppe Persiano, Duong Hieu Phan, Moti Yung

No abstract is available for this record.

Léo Robert, Daiki Miyahara, Pascal Lafourcade, Takaaki Mizuki

No abstract is available for this record.

Christian Badertscher, Peter Gaži, Iñigo Querejeta-Azurmendi, Alexander Russell

No abstract is available for this record.

Brett Hemenway, Sarah Hammer

No abstract is available for this record.

Mikołaj Barczentewicz

No abstract is available for this record.

Sudheer Chava, Fred Hu, Nikhil Paradkar

Abstract We proxy retail investor attention through Google Trends and find that fungible and non-fungible crypto tokens generate greater attention from high-gambling propensity regions. Crypto attention is higher during bubble-like episodes in the crypto market and for more lottery-like tokens. Moreover, retail crypto attention decreases after sports gambling is legalized. Higher token attention is associated with more contributors and higher fundraising. However, consumer credit default rates spike after periods of high crypto attention, but solely in the subprime segment. Overall, our findings suggest that gambling preferences strongly predict retail investor interest in the crypto market.

Md Haris Uddin Sharif

Bitcoin is one of many crypto currencies used for peer - to - peer transactions accessible to anyone with internet access. It is a decentralized digital currency not backed by any government or other legal entity, making it an attractive alternative to the traditional fiat money system. There is no doubt that crypto currencies are the future of money. However, not all crypto projects will succeed in the long run and some might even turn out to be scams. It?s a jungle out there! How do you know which crypt currency project is going to survive? Our paper can help you identify which projects have a good chance of survival by analyzing their market capitalization trends over time using equicorrelation analysis. This paper examines whether or not Bitcoin returns are dependent on common factors, investigates whether or not Bitcoin returns are i. i. d., tests the efficiency of crypt currency markets, and provides an answer to the following question: are crypto currencies efficient? We'll be looking at crypto currencies and their impact on financial markets. We'll also discuss the challenges of using crypto currencies as a predictor for later price movements and look at equicorrelation and its effect on the crypt currency market. We'll also discuss some of the challenges of using equicorrelation as a predictor for future price movements. Finally, we'll explore some potential applications for equicorrelation within the business world.

Mustafa Takaoğlu, Adem Özyavaş, Naim Ajlouni, Ali Alshahrani · 5 authors

Data security and data hiding have been studied throughout history. Studies show that steganography and encryption methods are used together to hide data and avoid detection. Large amounts of data hidden in the cover multimedia distort the image, which can be detected in visual and histogram analysis. The proposed method will solve two major drawbacks of the current methods: the limitation imposed on the size of the data to be hidden in the cover multimedia and low resistance to steganalysis after stego-operation. In the proposed method, plaintext data are divided into fixed-sized bits whose corresponding matching bits’ indices in the cover multimedia are accumulated. Thus, the hidden data are composed of the indices in the cover multimedia, causing no change in it, thus enabling considerable amounts of plaintext to be hidden. The proposed method also has high resistance to known steganalysis methods because it does not cause any distortion to the cover multimedia. The test results show that the performance of the proposed method outperforms similar conventional stenographic techniques. The proposed Ozyavas–Takaoglu–Ajlouni (OTA) method relieves the limitation on the size of the hidden data, and hidden data is undetectable by steganalysis because it is no longer embedded in the cover multimedia.

Kranthi Kumar Singamaneni, Kadiyala Ramana, Gaurav Dhiman, Saurabh Singh · 5 authors

As a result of the limited resources available in IoT local devices, the large scale cloud consumer's data that are produced by IoT related machines are contracted out to the cloud. Cloud computing is unreliable, using it can compromise user privacy, and data may be leaked. Because cloud-data and grid infrastructure are both growing exponentially, there is an urgent need to explore computational sources and cloud large-data protection. Numerous cloud service categories are assimilated into numerous fields, such as defense systems and pharmaceutical databases, to compute information space and allocation of resources. Attribute Based Encryption (ABE) is a sophisticated approach which can permit employees to specify a higher level of security for data stored in cloud storage facilities. Numerous obsolete ABE techniques are practical when applied to small data sets to generate cryptograms with restricted computational properties; their properties are used to generate the key, encrypt it, and decrypt it. To address the current concerns, a dynamic non-linear polynomial chaotic quantum hash technique on top of secure block chain model can be used for enhancing cloud data security while maintaining user privacy. In the proposed method, customer attributes are guaranteed by using a dynamic non- polynomial chaotic map function for the key initialization, encryption, and decryption. In the proposed model, both organized and unorganized massive clinical data are considered to be inputs for reliable corroboration and encoding. Compared to existing models, the real-time simulation results demonstrate that the stated standard is more precise than 90% in terms of bit change and more precise than 95% in terms of dynamic key generation, encipherment, and decipherment time.

Jie Ma, Bin Qi, Kewei Lv

Abstract In this paper, we propose a novel cryptographic primitive named reusable group fuzzy extractor (RGFE) allowing any member of a group to extract and reproduce random strings from a fuzzy and non-uniform source of high entropy (called fingerprint). Any group member can anonymously generate a random string for the group using his fingerprint and can be traced when needed, whereas other members can reproduce the string using their own fingerprints. Moreover, a fingerprint can be repeatedly used to generate multiple random strings. Basing on RGFE, we present group-shared Bitcoin wallet, which can be used by a group of users to receive or spend coins via biometrics in a traceable way.

Jilsa Chandarana, Rushit Ajudiya, Atharva Dattatreya, Rima Patel

In this fast-growing world, money has become a dominant asset. As the technology evolved, a new way of money transfer arose named Cryptocurrency. Cryptocurrency, also known as crypto, is a digital currency and has no physical form. Cryptocurrency is trending in finance and technical fields. It is very popular among investors as well. There is various cryptocurrency available in the market with different price and properties. The objective of this paper is to get familiar with cryptocurrency and compare different characteristics of top cryptocurrencies. The cryptocurrency listed in the paper were most likely to be found on any website about cryptocurrency. In this paper, an overview of all these cryptocurrencies is provided along with their prices. The list of top cryptocurrencies was taken from indiatoday.com and it was verified by other online sources.[1]

Aksa Isac John

Abstract: Evolution and modernization have brought about progress in technology and this has led to the reduction in privacy & internet security due to an increase in cybercrime and threats. As a result of this turn of events, Cryptography is now being used as a means of keeping information of any kind safe from third party individual(s). Research has shown that with the Encryption of information, third party individual(s) have no chance or less chance of getting past this security measure. Hence, Cryptographers keep improving algorithms to make it impossible for a third party to decrypt this information without the key which is where database Privacy and Security come in. The database contains all the information which is a major asset, there are encryptions which can be used at different levels to provide security. Lastly, for encryption algorithms which are breached by unknown third-party individual(s), the zero knowledge of proof helps to figure out the identity of this individual. They are an extremely interesting and useful construct. They are fascinating because of their definition, which is mutually opposed, their applicability is very vast in cryptography; they are used to restrict the malevolent users to work according to the protocol. Zero-knowledge serve as a good medium to understand the problems regarding cryptographic protocols. Keywords: Cipher, Encryption, Decryption, Key, Security, Database, Zero-Knowledge

Diego F. Aranha, Sebastian Berndt, Thomas Eisenbarth, Okan Seker · 7 authors

We study masking countermeasures for side-channel attacks against signature schemes constructed from the MPC-in-the-head paradigm, specifically when the MPC protocol uses preprocessing. This class of signature schemes includes Picnic, an alternate candidate in the third round of the NIST post-quantum standardization project. The only previously known approach to masking MPC-in-the-head signatures suffers from interoperability issues and increased signature sizes. Further, we present a new attack to demonstrate that known countermeasures are not sufficient when the MPC protocol uses a preprocessing phase, as in Picnic3.We overcome these challenges by showing how to mask the underlying zero-knowledge proof system due to Katz–Kolesnikov–Wang (CCS 2018) for any masking order, and by formally proving that our approach meets the standard security notions of non-interference for masking countermeasures. As a case study, we apply our masking technique to Picnic. We then implement different masked versions of Picnic signing providing first order protection for the ARM Cortex M4 platform, and quantify the overhead of these different masking approaches. We carefully analyze the side-channel risk of hashing operations, and give optimizations that reduce the CPU cost of protecting hashing in Picnic by a factor of five. The performance penalties of the masking countermeasures ranged from 1.8 to 5.5, depending on the degree of masking applied to hash function invocations.

Ujwal Patil, P. M. Chouragade

Nowadays, it is difficult to predict the information such as news and videos on the internet is real or not and people are increasingly sharing it on social media without thinking of fake. As soon as they verify the authenticity of a video, they start expressing their concerns and sharing the opinions of others. Therefore, such videos spread rapidly and help in sharing fake videos or unverified information. The need today is to focus on building a strong fake video detection system as soon as possible to avoid the consequences of such unverified information. This paper analyzes the recent research articles to detect the deep fake videos on social media.

Suthee Ruangwises

Nonogram is a pencil puzzle consisting of a rectangular white grid where the player has to paint some cells black according to given constraints. In 2010, Chien and Hon constructed a physical card-based zero-knowledge proof protocol for Nonogram, which enables a prover to physically show that he/she knows a solution of the puzzle without revealing it. However, their protocol requires special tools such as scratch-off cards and a sealing machine, making it impractical to implement in real world. The protocol also has a nonzero soundness error. In this paper, we develop a more practical card-based protocol for Nonogram with perfect soundness that uses only regular paper cards. We also show how to modify our protocol to make it support Nonogram Color, a generalization of Nonogram where the player has to paint the cells with multiple colors.

Surya Prakash Gupta, Kushagra Gupta, B. R. Chandavarkar

In today's world of digital media, people are mainly sharing all of their resources via digital platforms. Today, in almost all regions across the globe, the physical exchange of money is becoming less in practice. People are more flexible with buying and paying for their necessities via digital platforms rather than exchanging physical money. Cryptocurrency, the new global money for the internet age, is also a medium of exchange similar to other currencies. Still, here, the sole purpose of the exchange is via digital means. How secure is your cryptocurrency? How anonymous are users of cryptocurrencies? Since the currency is digital, it is more prone to attacks, data theft, and money. Here comes the role of cryptography. Cryptography is an essential mechanism for securing information in computer systems. Without cryptography, cryptocurrency is just a central hub for attackers and scammers. Cryptocurrency requires cryptography for mainly two purposes; to secure the transactions and to verify these transfers. This paper discusses the types of cryptographic techniques used in cryptocurrencies, studies their characteristics, and explores the working of these techniques.

Ji-Hwei Horng, Ching‐Chun Chang, Guanlong Li, Wai‐Kong Lee · 5 authors

Medical images carry a lot of important information for making a medical diagnosis. Since the medical images need to be communicated frequently to allow timely and accurate diagnosis, it has become a target for malicious attacks. Hence, medical images are protected through encryption algorithms. Recently, reversible data hiding on the encrypted images (RDHEI) schemes are employed to embed private information into the medical images. This allows effective and secure communication, wherein the privately embedded information (e.g., medical records and personal information) is very useful to the medical diagnosis. However, existing RDHEI schemes still suffer from low embedding capacity, which limits their applicability. Besides, such solution still lacks a good mechanism to ensure its integrity and traceability. To resolve these issues, a novel approach based on image block-wise encryption and histogram shifting is proposed to provide more embedding capacity in the encrypted images. The embedding rate is over 0.8 bpp for typical medical images. On top of that, a blockchain-based system for RDHEI is proposed to resolve the traceability. The private information is stored on the blockchain together with the hash value of the original medical image. This allows traceability of all the medical images communicated over the proposed blockchain network.

Shimin Jing, Xin Zheng, Zhengwen Chen

In cryptography, many different data structures are used to store and encrypt data. Merkle Tree is such a data structure that provides a way to prove data integrity and validity. It requires less memory or disk space than other data structures, resulting in simple and fast computation. This paper first explains the detailed principles and then introduces the application fields of Merkle Tree. Merkle Tree uses the hash value of the data block as leaf node tags and the encrypted hash of the child node tags as other node tags. As data structures evolve and innovate, Merkle Tree provides help and inspiration for the future new data structures. Furthermore, we investigate various applications using Merkle Tree technology, including Smart Grid, Bitcoin, Ethereum, Interplanetary File System, Image Authentication, Public Security Audit of Cloud Computing, SIMulator for Blockchain Applications, Hardware Memory Integrity, and Certificate Transparency. These researches show that Merkle Tree applies to a wide range of fields and has great potential. In brief, the paper aims to help researchers better understand the Merkle Tree features and various roles and effects in different environments, contributing to the development of cryptography.