Preimage Resistance Research Articles

Enhancing Blockchain Security by Developing the SHA256 Algorithm

Security plays a vital role in various domains, including blockchain technology. The Blockchain serves as a secure data structure for storing transactional records. Hash functions are employed in cryptography to ensure integrity and authentication within the blockchain. The widely used SHA256 algorithm has faced recent attacks, prompting the development of stronger hash functions. This paper presents a novel modification approach to enhance the performance of SHA256 by introducing an extended mechanism for generating a 288-bit message digest and reducing the number of rounds to 44 instead of 64 while preserving the diffusion of data through its complex iterative process, which involves multiple rounds of bitwise and logical operations. The change makes sure that even small changes to the input data cause noticeable variations in the output hash, thereby maintaining cryptographic properties. The suggested hash function SHA288 achieves improved security, collision resistance, and preimage resistance, while maintaining a faster execution time compared to SHA256. The tables and tests conducted on the suggested algorithm have revealed its remarkable safety and robustness in countering attacks as well as demonstrated outstanding performance in random tests, which further enhances its security measures.

Leveraging Cryptographic Hash Functions for Credit Card Fraud Detection

Credit card fraud remains a significant challenge in the financial industry, posing substantial financial losses to both consumers and businesses. Traditional fraud detection methods often rely on rule-based approaches and statistical models, which may struggle to keep pace with evolving fraud tactics and sophisticated cyber threats. In this paper, we propose a novel approach to credit card fraud detection leveraging cryptographic hash functions. Cryptographic hash functions offer robust security guarantees, including collision resistance and preimage resistance, making them well-suited for ensuring the integrity and authenticity of transaction data. Our proposed system employs cryptographic hash functions, such as SHA-256, to generate unique hash values for credit card transactions. These hash values serve as digital fingerprints of the transaction data, enabling secure verification and auditing of transactions on the blockchain. We conducted experiments using a dataset of 100,000 credit card transactions, evaluating the performance of our system in terms of accuracy, precision, recall, and F1-score. The results demonstrate the effectiveness of our approach in accurately identifying fraudulent transactions while minimizing false positives. Furthermore, we discuss the implications of our findings and explore future research directions, including the integration of advanced cryptographic techniques and blockchain technology to enhance the security and privacy of credit card transactions. Overall, our study underscores the importance of cryptographic hash functions in building robust and secure fraud detection systems capable of combating emerging fraud threats in the digital era.

A Second Preimage Attack on the XOR Hash Combiner

The exclusive-or (XOR) hash combiner is a classical hash function combiner, which is well known as a good PRF and MAC combiner, and is used in practice in TLS versions 1.0 and 1.1. In this work, we analyze the second preimage resistance of the XOR combiner underlying two different narrow-pipe hash functions with weak ideal compression functions. To control simultaneously the behavior of the two different hash functions, we develop a new structure called multicollision-and-double-diamond. Multicollision-and-double-diamond structure is constructed using the idea of meet-in-the-middle technique, combined with Joux’s multicollision and Chen’s inverse-diamond structure. Then based on the multicollision-and-double-diamond structure, we present a second preimage attack on the XOR hash combiner with the time complexity of about O2n+12n/2+n−l2n−l+n−k2n−k+2l+1+2k+1) (n is the size of the XOR hash combiner and l and k are respectively the depths of the two inverse-diamond structures), less than the ideal time complexity O2n, and memory of about O2k+2l.

Locality-Sensitive Hashing Does Not Guarantee Privacy! Attacks on Google's FLoC and the MinHash Hierarchy System

Recently proposed systems aim at achieving privacy using locality-sensitive hashing. We show how these approaches fail by presenting attacks against two such systems: Google's FLoC proposal for privacy-preserving targeted advertising and the MinHash Hierarchy, a system for processing location trajectories in a privacy-preserving way. Our attacks refute the pre-image resistance, anonymity, and privacy guarantees claimed for these systems. In the case of FLoC, we show how to deanonymize users using Sybil attacks and to reconstruct 10% or more of the browsing history for 30% of its users using Generative Adversarial Networks. We achieve this only analyzing the hashes used by FLoC. For MinHash, we precisely identify the location trajectory of a subset of individuals and, on average, we can limit users' trajectory to just 10% of the possible geographic area, again using just the hashes. In addition, we refute their differential privacy claims.

Automatic Preimage Attack Framework on Ascon Using a Linearize-and-Guess Approach

Ascon is the final winner of the lightweight cryptography standardization competition (2018 − 2023). In this paper, we focus on preimage attacks against round-reduced Ascon. The preimage attack framework, utilizing the linear structure with the allocating model, was initially proposed by Guo et al. at ASIACRYPT 2016 and subsequently improved by Li et al. at EUROCRYPT 2019, demonstrating high effectiveness in breaking the preimage resistance of Keccak. In this paper, we extend this preimage attack framework to Ascon from two aspects. Firstly, we propose a linearize-and-guess approach by analyzing the algebraic properties of the Ascon permutation. As a result, the complexity of finding a preimage for 2-round Ascon-Xof with a 64-bit hash value can be significantly reduced from 239 guesses to 227.56 guesses. To support the effectiveness of our approach, we find an actual preimage of all ‘0’ hash in practical time. Secondly, we develop a SAT-based automatic preimage attack framework using the linearize-and-guess approach, which is efficient to search for the optimal structures exhaustively. Consequently, we present the best theoretical preimage attacks on 3-round and 4-round Ascon-Xof so far.

Basic Cryptographic Concepts and Open Problems in Hash Function Security

JOHNNA SMITH, Dept of Mathematics, Shepherd University, Shepherdstown, WV, 25443, and DONALD MILLS, Dept of Computer Sciences, Mathematics, and Engineering, Shepherd University, Shepherdstown, WV, 25443. Analysis of basic cryptographic concepts and recent open problems in hash function security. 
 
 The objectives of this study are to show an understanding of cryptographic concepts as well as highlight recent open problems involving hash function security. The method of study used included reading the first five chapters of Cryptography: Theory and Practice by Stinson and Paterson as well as a recent paper that outlined open problems in hash function security. Then, written reports were delivered on the information learned which included selected proofs and solved examples. The essentials of the opening report introduce the basic elements of cryptography: cryptosystems, cryptographic tools, message integrity, protocols, and security approaches. Chapter 2 of “Cryptography” describes various types of ciphers including Shift, Substitution, Affine, Vigenère, Hill, Permutation, and Stream Ciphers, as well as how to cryptanalyze them. The third report focuses on the One-time Pad, entropy, perfect security, and cryptographic security, specifically unconditional security, as introduced by Claude Shannon in his work on information theory. Throughout the fourth report, block and stream ciphers, including substitution-permutation networks, attacks such as linear and differential cryptanalysis, and modes of operation are discussed. In the fifth report, basic concepts of cryptography, hash function and message authentication are discussed, including iterated hash function, sponge construction, and unconditionally secure MACS. Using the information learned from the previous reports, current problems in hash functions were then researched. In conclusion, open problems in hash function security include collision resistance, preimage resistance, and resistant to length extension attacks. The project was sponsored by the NSF S-STEM Grant (DUE-2130267).

Differential Analysis of a Cryptographic Hashing Algorithm HBC-256

The article observes the new hashing algorithm HBC-256. The HBC-256 algorithm is based on the block cipher of the compression function CF (Compression Function) and produces a 256-bits hash value. Like any new cryptographic structure, the HBC-256 algorithm requires careful research process in order to confirm its cryptographic properties, namely: pre-image resistance and resistance to collisions of the first and second order. As a result of the research, for the HBC-256 hashing algorithm differential properties of nonlinear elements (S-boxes) and various options for constructing round characteristics are considered. A hypothesis has been advanced about the existence of paired differences, which will make it possible to construct round characteristics for hashing and for the function of round keys generating. It is shown that even for the most optimal way of constructing chains of differences, the probability of finding correct pairs of texts is less than the probability of a complete enumeration of one 128-bit block of input data, which makes the method of differential cryptanalysis unsuitable for finding collisions.

Proof of Learning: Towards a Practical Blockchain Consensus Mechanism Using Directed Guiding Gradients (Student Abstract)

Since Bitcoin, blockchain has attracted the attention of researchers. The consensus mechanism at the center of blockchain is often criticized for wasting a large amount of computing power for meaningless hashing. At the same time, state-of-the-art models in deep learning require increasing computing power to be trained. Proof of Learning (PoL) is dedicated to using the originally wasted computing power to train neural networks. Most of the previous PoL consensus mechanisms are based on two methods, recomputation or performance metrics. However, in practical scenarios, these methods both do not satisfy all properties necessary to build a large-scale blockchain, such as certainty, constant verification, therefore are still far away from being practical. In this paper, we observe that the opacity of deep learning models is similar to the pre-image resistance of hash functions and can naturally be used to build PoL. Based on our observation, we propose a method called Directed Guiding Gradient. Using this method, our proposed PoL consensus mechanism has a similar structure to the widely used Proof of Work (PoW), allowing us to build practical blockchain on it and train neutral networks simultaneously. In experiments, we build a blockchain on top of our proposed PoL consensus mechanism and results show that our PoL works well.

A Guaranteed Secure Scan Design Based on Test Data Obfuscation by Cryptographic Hash

Design-for-testability (DfT) techniques have been widely adopted into the integrated circuit (IC) design process to facilitate manufacture testing. The scan-based DfT architecture is a popular DfT feature that provides full testability for the circuit under test. However, this turns into a double-edged sword for some ICs such as cryptographic chips because scan design could be used as a side channel to access the intermediate encryption results, with which the cipher key can be deduced easily. To resist such scan-based side-channel attacks, many countermeasures are proposed to obfuscate the test data in scan chain. Unfortunately, most of the obfuscation logic, due to the performance and resource constraints, cannot be proven to be irreversible and hence suffers a high risk for the correct test data being derived from the obfuscated output. In this article, we propose to utilize the cryptographic hash module for some post-processing of the test responses in order to secure the scan design. Our approach has several clear advantages over existing ones. First, the security is guaranteed based on the preimage resistance of cryptographic hash function and the introduced salt information and data collection scheme. Second, it incurs low overhead because the hash module is normally available on the IC, in particular, those where security is important. Finally, full testability is retained as we are not modifying any test input. We present the implementation of the proposed secure design, report the experimental results, and demonstrate that our approach can resist all known scan-based side-channel attacks with negligible overhead while maintaining the testability and other testing performances.

Generic Attacks on Hash Combiners

Hash combiners are a practical way to make cryptographic hash functions more tolerant to future attacks and compatible with existing infrastructure. A combiner combines two or more hash functions in a way that is hopefully more secure than each of the underlying hash functions, or at least remains secure as long as one of them is secure. Two classical hash combiners are the exclusive-or (XOR) combiner \( \mathcal {H}_1(M) \oplus \mathcal {H}_2(M) \) and the concatenation combiner \( \mathcal {H}_1(M) \Vert \mathcal {H}_2(M) \). Both of them process the same message using the two underlying hash functions in parallel. Apart from parallel combiners, there are also cascade constructions sequentially calling the underlying hash functions to process the message repeatedly, such as Hash-Twice \(\mathcal {H}_2(\mathcal {H}_1(IV, M), M)\) and the Zipper hash \(\mathcal {H}_2(\mathcal {H}_1(IV, M), \overleftarrow{M})\), where \(\overleftarrow{M}\) is the reverse of the message M. In this work, we study the security of these hash combiners by devising the best-known generic attacks. The results show that the security of most of the combiners is not as high as commonly believed. We summarize our attacks and their computational complexities (ignoring the polynomial factors) as follows:1.Several generic preimage attacks on the XOR combiner:A first attack with a best-case complexity of \( 2^{5n/6} \) obtained for messages of length \( 2^{n/3} \). It relies on a novel technical tool named interchange structure. It is applicable for combiners whose underlying hash functions follow the Merkle–Damgård construction or the HAIFA framework.A second attack with a best-case complexity of \( 2^{2n/3} \) obtained for messages of length \( 2^{n/2} \). It exploits properties of functional graphs of random mappings. It achieves a significant improvement over the first attack but is only applicable when the underlying hash functions use the Merkle–Damgård construction.An improvement upon the second attack with a best-case complexity of \( 2^{5n/8} \) obtained for messages of length \( 2^{5n/8} \). It further exploits properties of functional graphs of random mappings and uses longer messages. These attacks show a rather surprising result: regarding preimage resistance, the sum of two n-bit narrow-pipe hash functions following the considered constructions can never provide n-bit security.2.A generic second-preimage attack on the concatenation combiner of two Merkle–Damgård hash functions. This attack finds second preimages faster than \( 2^n \) for challenges longer than \( 2^{2n/7} \) and has a best-case complexity of \( 2^{3n/4} \) obtained for challenges of length \( 2^{3n/4} \). It also exploits properties of functional graphs of random mappings.3.The first generic second-preimage attack on the Zipper hash with underlying hash functions following the Merkle–Damgård construction. The best-case complexity is \( 2^{3n/5} \), obtained for challenge messages of length \( 2^{2n/5} \).4.An improved generic second-preimage attack on Hash-Twice with underlying hash functions following the Merkle–Damgård construction. The best-case complexity is \( 2^{13n/22} \), obtained for challenge messages of length \( 2^{13n/22} \).The last three attacks show that regarding second-preimage resistance, the concatenation and cascade of two n-bit narrow-pipe Merkle–Damgård hash functions do not provide much more security than that can be provided by a single n-bit hash function. Our main technical contributions include the following:1.The interchange structure, which enables simultaneously controlling the behaviours of two hash computations sharing the same input.2.The simultaneous expandable message, which is a set of messages of length covering a whole appropriate range and being multi-collision for both of the underlying hash functions.3.New ways to exploit the properties of functional graphs of random mappings generated by fixing the message block input to the underlying compression functions.

Light-weight hashing method for user authentication in Internet-of-Things

The goal of Internet-of-Things (IoT) is that every object across the globe be interconnected under the Internet Infrastructure. IoT is expanding its application domain to range from environmental monitoring to industrial automation thereby leading to vast research challenges. Vast presence of devices in the Internet has increased the possible challenges faced by devices and data. The devices communicate on a public channel that is more likely to be accessed by unauthorized users and disturb the privacy of genuine users. The existing solutions that ensure data authenticity and user privacy, use MD5 and SHA-family of hashing algorithms under digital signature schemes. These algorithms create a trade-off between the security concern and energy consumption of IoT devices. To provide an energy efficient authentication method, we propose a customized BLAKE2b hashing algorithm with modified elliptic curve digital signature scheme (ECDSA). The parameters considered for the evaluation of the proposed methods are signature generation time, signature verification time and hashing time. The experiments are conducted under client server model using Raspberry Pi-3. The proposed method has shown about 0.7–1.91% improvement in the signature generation time and 7.67–9.13 % improvement in signature verification time when compared with BLAKE2b based signature generation/verification. The proposed method is resistant to Man-in-the-Middle attack, Distributed DoS attack (DDoS), pre-image resistance, second pre-image resistance and collision resistance. Based on the performance obtained by the experiments, it can be inferred that the proposed scheme is feasible for resource-constrained IoT devices.

Implementation of high speed hash function Keccak on GPU

Nowadays, a hash function is used for password management. The hash function is desired to possess the following three characteristics: Pre-Image Resistance, Second Pre-Image Resistance, and Collision Resistance. They are set on the assumption that it is computationally difficult to find the original message from a given hash value. However, the security level of the password management will be further reduced by implementing a high speed hash function on GPU. In this paper, the implementation of high speed hash function Keccak-512 using the integrated development environment CUDA for GPU is proposed. The following four techniques are used in order to speed up its implementation. The first one is reforming lookup tables from 2 dimensional arrays to 1 dimensional arrays at step rho and pi. The second is an investigation into the effect of using constant memory and shared memory for constant values. The third is the finding out the optimal configuration of blocks-threads, then evaluate the implementation according to the occupancy. And the last one is using CUDA streams with overlapping to hide the overhead of data transfer and GPU processing. As the result, the throughput of implemented Keccak on GeForce GTX 1080 achieved up to maximum 64.58 GB/s. It is about 14.0 times faster than the previous research result. In addition, the safety level of Keccak is also discussed at the point of Pre-Image Resistance especially. In order to implement a high speed hash function for password cracking, we developed a special program for passwords up to 71 characters. Moreover, the throughputs of 2 times as well as 3 times hash are also evaluated. It is proved that multiple times hash is possible to greatly improved the security level of Keccak with password management. The throughput of hashing password with a large number of iterations confirmed the effect was about 90%. That is the time required to hash one password for 1000 times was almost the same as the total time to sequentially hash 900 passwords.

Sequential Hashing with Minimum Padding

This article presents a sequential domain extension scheme with minimum padding for hashing using a compression function. The proposed domain extension scheme is free from the length extension property. The collision resistance of a hash function using the proposed domain extension is shown to be reduced to the collision resistance and the everywhere preimage resistance of the underlying compression function in the standard model, where the compression function is assumed to be chosen at random from a function family in some efficient way. Its indifferentiability from a random oracle up to the birthday bound is also shown on the assumption that the underlying compression function is a fixed-input-length random oracle or the Davies-Meyer mode of a block cipher chosen uniformly at random. The proposed domain extension is also applied to the sponge construction and the resultant hash function is shown to be indifferentiable from a random oracle up to the birthday bound in the ideal permutation model. The proposed domain extension scheme is expected to be useful for processing short messages.

On quantum (δ, є)-resistant hashing

In the paper we define a notion of quantum resistant ((δ, є)-resistant) hash function which combine together a notion of pre-image (one-way) resistance (δ-resistance) property and the notion of collision resistance (є-resistance) properties. We present a discussion that supports the idea of quantum hashing oriented for cryptographical purposes. We propose a quantum setting of a classical digital signature scheme do demonstrate a theoretical possibilities and restrictions of (δ, є)-hashing. The assumption we use is that a set of qubits (quantum hash) we generate, send, and receive during the execution of a protocol can be stored for a certain (a large enough) amount of time; next, the scheme requires the high degree of entanglement between the qubits which makes such a quantum hash. These properties make quantum hash cryptographically efficient.

Variable message encryption through blockcipher compression function

SummaryA constrained device is an emerging technology that has enormous applications in our daily life such as access control, inventory control, luggage tracking, bar‐code reader, and IoT. However, it has certain drawbacks of low memory and less computing power. Thus, one of the cracking challenges is to provide efficient and secure cryptographic solution for the constrained device in the aspect of security issue. An (n,n) blockcipher‐based cryptographic compression function is applicable to provide provable security to the constrained device. Though, there are many constructions of (n,n) blockcipher such as MDC‐2, MDC‐4, MJH, Bart‐12, and SKS‐15. However, most of the familiar schemes are not suitable for short and variable message encryption without padding because of their internal structures. Furthermore, the security margin is provided based on blocklength rather than the flexible size of message. In this paper, we present two different (n,n) blockcipher compression function schemes. The first scheme (FS) satisfies better efficiency such as less call of blockcipher, less key scheduling, and higher efficiency rate. On the contrary, the second scheme (SS) has upper security bound. Moreover, both of the schemes are suitable for small and variable message encryption (message size = tn|t < 1,n:blocklength), which is handy for the constrained device. The collision and preimage security bound of the FS are O(2tn/2) and O(2tn). In addition, the SS's collision resistance and preimage resistance are bounded by O(2tn) and O(22tn). Moreover, the efficiency rate of the proposed two schemes are respectively t and t/3. The numbers of key scheduling are 2 for the constructions of FS and SS. We use two calls of blockcipher in the FS. On the contrary, three calls of blockcipher are used in the SS. Copyright © 2016 John Wiley & Sons, Ltd.

Binary quantum hashing

We propose a binary quantum hashing technique that allows to present binary inputs by quantum states. We prove the cryptographic properties of the quantum hashing, including its collision resistance and preimage resistance. We also give an efficient quantum algorithm that performs quantum hashing, and altogether this means that this function is quantum one-way. The proposed construction is asymptotically optimal in the number of qubits used.

Optimal collision security in double block length hashing with single length key

The idea of double block length hashing is to construct a compression function on 2n bits using a block cipher with an n-bit block size. All optimally secure double block length hash functions known in the literature employ a cipher with a key space of double block size, 2n-bit. On the other hand, no optimally secure compression functions built from a cipher with an n-bit key space are known. Our work deals with this problem. Firstly, we prove that for a wide class of compression functions with two calls to its underlying n-bit keyed block cipher collisions can be found in about $$2^{n/2}$$2n/2 queries. This attack applies, among others, to functions where the output is derived from the block cipher outputs in a linear way. This observation demonstrates that all security results of designs using a cipher with 2n-bit key space crucially rely on the presence of these extra n key bits. The main contribution of this work is a proof that this issue can be resolved by allowing the compression function to make one extra call to the cipher. We propose a family of compression functions making three block cipher calls that asymptotically achieves optimal collision resistance up to $$2^{n(1-\varepsilon )}$$2n(1-ź) queries and preimage resistance up to $$2^{3n(1-\varepsilon )/2}$$23n(1-ź)/2 queries, for any $$\varepsilon >0$$ź>0. To our knowledge, this is the first optimally collision secure double block length construction using a block cipher with single length key space. We additionally prove this class of functions indifferentiable from random functions in about $$2^{n/2}$$2n/2 queries, and demonstrate that no other function in this direction achieves a bound of similar kind.

A novel keyed parallel hashing scheme based on a new chaotic system

Hash functions play important role in the information security era. Although there are different methods to design these functions, in recent years chaos theory has emerged as a strong solution in this area. Chaotic hash functions use one-dimensional maps such as logistic and tent, or employ complex multi-dimensional maps which are typically insecure or slow and most of them has been successfully attacked. In this paper, we propose a new chaotic system and employ it to design a secure and fast hash function. The improved security factor has roots in the hyper sensitivity of the proposed chaotic map while properties like speed and security can be parameterized. On the other hand, the proposed hash function has a dynamic random array of functions and can be implemented by a parallel architecture. This data-level parallel architecture makes it fast to generate the hash value. Statistical simulations show success of the proposed hashing scheme. Cryptanalysis of proposed function, such as key sensitivity, meet-in-the-middle attack, collision, preimage resistance and high level attacks, proves security of the proposed function.

TDHA: A Timestamp Defined Hash Algorithm for Secure Data Dissemination in VANET

The safety application in vehicular ad hoc network provides active road safety to avoid road accidents by disseminating life critical information among drivers securely. Such information must be protected from the access of intruder or attacker. A timestamp defined hash algorithm is proposed in the present work for secure data dissemination among vehicles. The sender vehicle sends a deformed version of the original message along with the incomplete message digest to its neighbors. The receiver vehicle generates message digest from the deformed version of the original message and also from the incomplete message digest. It accepts the message if both the digests are equal. The proposed algorithm fulfils all the basic properties such as preimage resistance, collision resistance of a one-way unkeyed hash function. Finally the comparative usability of the hash algorithm in the said application domain is worked out and that shows the dominance of the scheme over the existing schemes.

On the balanced quantum hashing

In the paper we define a notion of a resistant quantum hash function which combines a notion of pre-image (one-way) resistance and the notion of collision resistance. In the quantum setting one-way resistance property and collision resistance property are correlated: the “more” a quantum function is one-way resistant the “less” it is collision resistant and vice versa. We present an explicit quantum hash function which is “balanced” one-way resistant and collision resistant and demonstrate how to build a large family of balanced quantum hash functions.