Birthday Attack Research Articles

Composite fixed-length ordered features with index-of-max transformation for high-performing and secure palmprint template protection

Palmprint recognition has attracted considerable attention due to its advantages over other biometric modalities such as fingerprints, in that it is larger in area, richer in information and able to work at a distance. However, the issue of palmprint privacy and security (especially palmprint template protection) remains under-studied. Among the very few research works, most of them only use orientational features of the palmprint with transformation processing, yielding unsatisfactory recognition and protection performance. Thus, this research work proposes a palmprint feature extraction method for palmprint template protection that is fixed-length and ordered in nature, by fusing point features and orientational features. Firstly, dual orientations are extracted and encoded with more accuracy based on the modified finite Radon transform (MFRAT). Then, SURF feature points are extracted and converted to be fixed-length and ordered features. Finally, composite fixed-length ordered features that fuse up the dual orientations and SURF points are transformed using the irreversible transformation of index-of-max (IoM) to generate the revocable palmprint templates. Experiments show that the matching accuracy of the proposed method of fixed-length and ordered point features are superior to all other feature extraction methods on the PolyU and CASIA datasets. It is also demonstrated that the EERs before and after IoM transformation are better than all other representative template protection methods. A thorough security and privacy analysis including brute-force attack, false accept attack, birthday attack, attack via record multiplicity, irreversibility, unlinkability and revocability is also given, which proves that our proposed method has both high performance and security.

A secure data transmission framework for IoT enabled healthcare

The Internet of Medical Things (IoMT) has transformed healthcare by connecting medical devices, sensors, and patients, significantly improving patient care. However, the sensitive data exchanged through IoMT is vulnerable to security attacks, raising serious privacy concerns. Traditional key sharing mechanisms are susceptible to compromise, posing risks to data integrity. This paper proposes a Timestamp-based Secret Key Generation (T-SKG) scheme for resource-constrained devices, generating a secret key at the patient's device and regenerating it at the doctor's device, thus eliminating direct key sharing and minimizing key compromise risks. Simulation results using MATLAB and Java demonstrate the T-SKG scheme's resilience against guessing, birthday, and brute force attacks. Specifically, there is only a 9 % chance of key compromise in a guessing attack if the attacker knows the key sequence pattern, while the scheme remains secure against brute force and birthday attacks within a specified timeframe. The T-SKG scheme is integrated into a healthcare framework to securely transmit health vitals collected using the MySignals sensor kit. For confidentiality, the Data Encryption Standard (DES) with various Cipher Block modes (ECB, CBC, CTR) is employed.

Key space estimation and security analysis of superlattice physical unclonable function

The key space, a crucial metric in discerning the strength of PUFs, holds significant importance for their security. However, there is insufficient research on superlattice PUFs. This paper integrates superlattice into the PUF theory framework, exploring its physical mechanisms and properties. The focus is on estimating the key space of superlattice PUFs and conducting a security analysis, encompassing resistance to brute force cracking, birthday attacks, and cloning attacks. The results show that its key space can be up to 24,500×50, with a huge number of Challenge-Response Pairs (CRP) set, belonging to strong PUF. It has significant advantages over conventional PUFs, making it applicable in the domains of cryptography and information security.

Key Committing Security of AEZ and More

For an Authenticated Encryption with Associated Data (AEAD) scheme, the key committing security refers to the security notion of whether the adversary can produce a pair of distinct input tuples, including the key, that result in the same output. While the key committing security of various nonce-based AEAD schemes is known, the security analysis of Robust AE (RAE) is largely unexplored. In particular, we are interested in the key committing security of AEAD schemes built on the Encode-then-Encipher (EtE) approach from a wide block cipher. We first consider AEZ v5, the classical and the first dedicated RAE that employs the EtE approach. We focus our analysis on the core part of AEZ to show our best attacks depending on the length of the ciphertext expansion. In the general case where the Tweakable Block Cipher (TBC) is assumed to be ideal, we show a birthday attack and a matching provable security result. AEZ adopts a simpler key schedule and the prove-then-prune approach in the full specification, and we show a practical attack against it by exploiting the simplicity of the key schedule. The complexity is 227, and we experimentally verify the correctness with a concrete example. We also cover two AEAD schemes based on EtE. One is built on Adiantum, and the other one is built on HCTR2, which are two wide block ciphers that are used in real applications. We present key committing attacks against these schemes when used in EtE and matching proofs for particular cases.

Committing Security of Ascon: Cryptanalysis on Primitive and Proof on Mode

Context-committing security of authenticated encryption (AE) that prevents ciphertexts from being decrypted with distinct decryption contexts, (K,N,A) comprising a key K, a nonce N, and associate data A is an active research field motivated by several real-world attacks. In this paper, we study the context-committing security of Ascon, the lightweight permutation-based AE selected by the NIST LWC in 2023, for cryptanalysis on primitive and proof on mode. The attacker’s goal is to find a collision of a ciphertext and a tag with distinct decryption contexts in which an attacker can control all the parameters including the key. First, we propose new attacks with primitives that inject differences in N and A. The new attack on Ascon-128 improves the number of rounds from 2 to 3 and practically generates distinct decryption contexts. The new attack also works in a practical complexity on 3 rounds of Ascon-128a. Second, we prove the context-committing security of Ascon with zero padding, namely Ascon-zp, in the random permutation model. Ascon-zp achieves min {t+z/2 , n+t−k−ν/2 , c/2}-bit security with a t-bit tag, a z-bit padding, an n-bit state, a ν-bit nonce, and a c-bit inner part. This bound corresponds to min {64 + z/2 , 96} with Ascon-128 and Ascon-128a, and min {64 + z/2 , 80} with Ascon-80pq. The original Ascon (z = 0) achieves 64-bit security bounded by a generic birthday attack. By appending zeroes to the plaintext, the security can be enhanced up to 96 bits for Ascon-128 and Ascon-128a and 80 bits for Ascon-80pq.

Modeling of blockchain with encryption based secure education record management system

Blockchain technology can be employed in the education sector by building a decentralized system to store and share student records. The records can be encrypted to guarantee their confidentiality and security. With a blockchain-based system, student records can be saved in blocks that are linked and secured via cryptography. The records are decentralized and not controlled by any single entity, making them less susceptible to hacking or tampering. By using blockchain technology, educational institutions can create a more secure and efficient system for storing and sharing student records. This can streamline the process of transferring records between schools, and provide a secure and transparent way for students to access their own records. In this study, we provide a novel Merkle tree-based strategy for preserving the accuracy of student records and outline how to put it into practice. The software architecture resembled blockchain technology and was developed for private network deployment. The key components of our strategy are replacing conventional audit trails with their cryptographically secure equivalent and simplifying the Blockchain framework by avoiding mining. The cryptography system's framework is presented, and the new five dimensions of chaotic map academic records are proposed. Our study utilizes deoxyribonucleic acid (DNA) sequences and operations and the chaotic system to strengthen the cryptosystem in the blockchain authentication and authorization process. The significant advantage of this method is enhancing the generation of the hash function, which is the most critical challenge in the blockchain concept. The experimental outcomes and security analysis demonstrated that the proposed method works well in terms of different aspects. The suggested hash function's hash value distribution, sensitivity to tiny message modifications, confusion and diffusion qualities, resilience against birthday attacks, keyspace analysis, collision resistance, efficiency, and flexibility were all considered throughout the study.

Deep self-learning based dynamic secret key generation for novel secure and efficient hashing algorithm

The hash function is an efficient source of the integrity and authentication of input text and other data messages (image & audio-video) in the cryptography field. Existing hashing algorithms are time-consuming and vulnerable to collision attacks, birthday attacks, meet-in-the-middle attacks, and key search attacks. In this context, we propose an innovative and secure hash algorithm that uses self-learning neurons during the implementation phase. Firstly, the proposed deep learning hashing algorithm accepts the variable length (ln) of the input text and image messages (im) at the input layer 0 and divides the whole input (M) into four characters, represented as message pair (MP). If the last MP contains less than four characters, have been completed by the assumption of the special cases and processed via the OR logical operation. Subsequently, the proposed pattern matching-swapping methods have resolved the conflict of the repeated characters in each MP. Secondly, the proposed novel dynamic secret keys are generated for each MP by introducing a skip and select basic conditions by omitting the consecutive 0's or 1's in key selection. Thirdly, upon successfully processing the phases above, the proposed novel hashing algorithm generates collision-free hash values using forwarding and backward propagation. Experimental results show that our proposed hashing algorithm is efficient and significantly outperforms in terms of sensitivity generated in hash output, speed, and collision resistance compared to the existing state-of-the-art hashing algorithms.

Chaotic neural networks and farfalle construction based parallel keyed secure hash function

AbstractParallel computing of hash functions along with the security requirements have great advantage in order to reduce the time consumption and overhead of the CPU. In this article, a keyed hash function based on farfalle construction and chaotic neural networks (CNNs) is proposed, which generates a hash value with arbitrary (defined by user) length (eg, 256 and 512 bits). The proposed hash function has parallelism merit because it is built over farfalle construction which avoids the dependency between the blocks of a given message. Moreover, the proposed hash function is chaos based (ie, it relies on chaotic maps and CNNs which have non‐periodic behavior). The security analysis shows that the proposed hash function is robust and satisfies the properties of hash algorithms, such as random‐like (non‐periodic) behavior, ideal sensitivity to original message and secret key, one‐way property and optimal diffusion effect. The speed performance of the hash function is also analyzed and compared with a hash function which was built based on sponge construction and CNN, and compared with secure hash algorithm (SHA) variants like SHA‐2 and SHA‐3. The results have shown that the proposed hash function has lower time complexity and higher throughput especially with large size messages. Additionally, the proposed hash function has enough resistance to multiple attacks, such as collision attack, birthday attack, exhaustive key search attack, preimage and second preimage attacks, and meet‐in‐the‐middle attack. These advantages make it ideal to be used as a good collision‐resistant hash function.

Continuous-time quantum hash function based on one-dimensional cycle lattice

The proposed quantum hash function (QHF) based on the discrete-time quantum walk (DTQW) structure requires enlarging the coin state space and the preparation of continuous quantum states is less difficult. Hence, a new construction method of QHF is proposed based on the continuous-time quantum walk (CTQW) of the one-dimensional (1D) lattice with boundary constraints and without additional coin space. In the scheme, the input of the QHF is an arbitrary binary string message which is used to control the selected Hamiltonian of CTQW at each time interval, and the output of the QHF is the final probability distribution of CTQW. Under the same computing environment, simulation and analysis indicate that our QHF can satisfy the same security requirements such as sensitivity, diffusion and confusion, collision, birthday attack, but the collision rate is reduced by 40% without reducing effectiveness.

A blockchain-based protocol for tracking user access to shared medical imaging

Modern healthcare systems are complex and regularly share sensitive data among multiple stakeholders, such as doctors, patients, and pharmacists. Patients’ data has increased and requires safe methods for its management. Research works related to blockchain, such as MIT MedRec, have strived to draft trustworthy and immutable systems to share data. However, blockchain may be challenging in healthcare scenarios due to issues about privacy and control of data sharing destinations. This paper presents a protocol for tracking shared medical data, which includes images, and controlling the medical data access by multiple conflicting stakeholders. Several efforts rely on blockchain for healthcare, but just a few are concerned about malicious data leakage in blockchain-based healthcare systems. We implement a token mechanism stored in DICOM files and managed by Hyperledger Fabric Blockchain. Our findings and evaluations revealed low chances of a hash collision, such as employing a fitting-resistance birthday attack. Although our solution was devised for healthcare, it can inspire and be easily ported to other blockchain-based application scenarios, such as Ethereum or Hyperledger Besu for business networks.

Asymptotically Guaranteed Anti-Jamming Spread Spectrum Random Access Without Pre-Shared Secret

Our main contribution is the design of a spread spectrum random access scheme without pre-shared secret with asymptotically guaranteed availability against electronic/cyber-based jamming attacks. In order to establish asymptotic anti-jamming guarantees, first we develop the system model and show that for reactive jamming (only limited by the laws of physical propagation), the required location for a successful attack can be controlled by design. Then, for non-reactive protocol-aware jamming, we map a random selection of (publicly known) spreading codes to the computational birthday problem. Differently to the related literature, we formulate the birthday problem using entropic measures (Rényi entropy), which allows to obtain the optimal spreading code set sizes that guarantee asymptotically zero collision probability. Accordingly, the birthday attack is the best strategy to optimize the (trial and error) blind acquisition at the legitimate detector. We obtain numerical results that illustrate how to use our entropic method as a system design degree of freedom to identify realistic spreading code set sizes. We also derive an upper bound of the detection latency. Finally, we show that the resulting anti-jamming throughput is higher than the throughput under conventional operation (i.e. without anti-jamming guarantees) due to the control of collision probability by-design.

Stability of password authentication in infocommunication networks

The article discusses distributed infocommunication networks, in which the interaction of users, application servers and databases is carried out. When accessing an infocommunication network, the first procedure is to authenticate the agents through their authentication by password mechanism. It is shown that for social networks with a large number of users, widely used assessment of the security of password systems based on the calculation of the determination probability is not sufficient. The probability of the same passwords for two users with a password length of 6, 7 and 8 characters with alphabet size of 36, 42 and 57 characters and the number of users no more than 10 million is shown. An assessment of the strength of password authentication systems for info-communication networks based on the birthday paradox criterion is given. It has been determined that well-known social networks with a number of users comparable to the number of passwords used are not resistant to birthday attacks. It is shown that for such systems the resistance of the password system to cracking should be assessed by m=A n/2 criterion.

Privacy-Preserving Certificate Linkage/Revocation in VANETs Without Linkage Authorities

Vehicular communication (V2X) technologies are expected to become common in the future, providing better efficiency and safety in transportation. This envisioned large-scale deployment, however, critically depends on addressing some issues. In special, to prevent abuse by drivers, messages exchanged among authorized vehicles must be authenticated. This implies the need of a Vehicular Public Key Infrastructure (VPKI). Unlike traditional PKIs, though, VPKIs are also expected to preserve the privacy of honest drivers, preventing their vehicles from being easily identified or tracked. One promising VPKI solution, which copes with such requirements and is among the main candidates for standardization in the United States, is the Security Credential Management System (SCMS). In this paper, aiming to enhance and address shortcomings identified in SCMS, we provide two main contributions. First, we describe and fix two birthday attacks against SCMS's certificate revocation process, thus improving the system's long-term privacy. Second, we propose a method that simplifies SCMS's architecture, removing the need for Linkage Authorities (LAs); this approach cuts down deployment costs while reducing the system's attack surface, in particular against some troublesome forms of replay attacks that are hereby unveiled.

Optimizing Hash Strategy to Avoid Birthday Attack

It is necessary to optimize hash codes to prevent birthday attacks. First of all, it is necessary to know what hash codes are, what birthday attacks are, and how to attack them. In this article, there are two ways to avoid birthday attacks: enlarge hash space andselection of magic number. After the implementation of different code and different magic number selection, the most stable and secure one will be chosen.

Palmprint template protection scheme based on randomized cuckoo hashing and MinHash

To provide the necessary security and privacy privileges for registered users of biometric systems, a novel template protection method for generating cancelable palmprint features based on randomized cuckoo hashing and minHash is proposed in this paper. Firstly, the orthogonal features of palmprint are extracted using the anisotropic filter. Then, a novel randomized cuckoo hashing is applied on the binary palmprint feature as a means of first layer security. Randomized cuckoo hashing composes of two hash tables; before hashing, each column of original biometric template is filtered with a random matrix to improve discriminative ability. For the randomized cuckoo hashing with the same positions, we use different Gray coding methods instead, which improves irreversibility. Furthermore, to improve the efficiency and resist unlinkability attacks, another layer of privacy protection, MinHash is adopted. Experimental results on PolyU database show that our method can nearly preserve the original verification performance. The irreversibility, unlinkability and revocability properties are examined experimentally. Also, the privacy of palmprint protection scheme is analyzed under the Brute-force Attack, False Accept Attack and Birthday attack.

HMNT: Hash Function Based on New Mersenne Number Transform

In the field of information security, hash functions are considered important as they are used to ensure message integrity and authentication. Despite various available methods to design hash functions, the methods have been proven to time inefficient and have security flaws (such as a lack of collision resistance or susceptibility to birthday attacks). In the current study, we propose a novel hash function scheme based on a new Mersenne number transform. The suggested hash function called Hash Mersenne Number Transform (HMNT) takes an arbitrary length as input to generate a hash value with variable lengths (128, 256 and 512-bits or longer). The proposed scheme is evaluated in terms of the sensitivity of the hash value to the message, secret key and image, distribution of hashes, confusion and diffusion, robustness against collision and birthday attacks, alongside flexibility. Based on the simulation outcomes, the suggested scheme possess high sensitivity to the original message, the secret key and images, along with strong collision resistance. In conclusion, the proposed hash scheme is simple and efficient compared with the existing hash functions, making it viable for practical implementation.

Password security by encryption using an extended ADFGVX cipher

Login will be the critical step for most of the web users for the user authentication. As hackers utilizing a variety of techniques to steal the passwords, it is recommended to offer secured transmission of passwords to the servers from the client system. Current web developers are using common traditional hashing techniques for securing passwords over the network. However, hashing techniques are vulnerable to several attacks like brute-force attack, dictionary attack, and birthday attack. This paper implemented password security with an easy and robust transposition based encryption technique using an extended ADFGVX cipher. The proposed cipher uses two 7 × 6 Polybius squares for encryption to accommodate common characters of the password along with the random key for encryption. Finally, this study considered four metrics for performance evaluation and compared the proposed method with the state-of-art techniques. It is found that the proposed method performed excellently regarding complexity for cracking password and satisfactorily concerning execution time.

Faster multicollision attack on Davies-Meyer hash function scheme implementing Simeck32/64 block cipher algorithm

Davies-Meyer is one scheme among 12 compression functions found through systematic analysis by Preneel et al. to be provably secure under black-box analysis. But in the development, this scheme proved to be vulnerable to fixed-point attack. With this vulnerability, it is possible to implement one of attack in an iterated hash function that exploits fixed-point weakness named faster multicollision attack. Implementing Simeck32/64 as an underlying block cipher, the attack induced by firstly searching for fixed-point collisions. To accomplish this finding stage based on Yuval’s birthday attack, a sum of 2.2n/2 different fixed-point sequences are needed. Based on that, two sets of 216 different inputs are generated by modifying 16 bits of least significant bits from each pair of five input samples to find a collision between them. The final result makes an outstanding fact, with 4.194.304 total collisions obtained from five samples and 16 different IV values that already produced before in fixed-point collision finding stage. These facts conclude that Davies-Meyer scheme is not resistance against faster multicollision attack because of its fixed-point weakness.

Hardness-Preserving Reductions via Cuckoo Hashing

The focus of this work is hardness-preserving transformations of somewhat limited pseudorandom functions families (PRFs) into ones with more versatile characteristics. Consider the problem of domain extension of pseudorandom functions: given a PRF that takes as input elements of some domain $$\mathcal {U}$$ , we would like to come up with a PRF over a larger domain. Can we do it with little work and without significantly impacting the security of the system? One approach is to first hash the larger domain into the smaller one and then apply the original PRF. Such a reduction, however, is vulnerable to a “birthday attack”: after $$\sqrt{\left| \mathcal {U}\right| }$$ queries to the resulting PRF, a collision (i.e., two distinct inputs having the same hash value) is very likely to occur. As a consequence, the resulting PRF is insecure against an attacker making this number of queries. In this work, we show how to go beyond the aforementioned birthday attack barrier by replacing the above simple hashing approach with a variant of cuckoo hashing, a hashing paradigm that resolves collisions in a table by using two hash functions and two tables, cleverly assigning each element to one of the two tables. We use this approach to obtain: (i) a domain extension method that requires just two calls to the original PRF can withstand as many queries as the original domain size, and has a distinguishing probability that is exponentially small in the amount of non-cryptographic work; and (ii) a security-preserving reduction from non-adaptive to adaptive PRFs.

A Parallel Hash Function with Variable Initial Values

In recent years, considerable effort has been devoted to research on hash function. Nevertheless, it’s hard to obtain the proporties of sensitivity, confusion and diffusion, collision resistance, and high efficiency simultaneously. Based on research of all attacks to classical hash functions, we propose a parallel and collision resistance hash function. With regard to the design of compression function, in order to resist attacks, such as birthday attack, forgery attack and multi-collision attack, we change the initial value of the chaining variable, which is processed through three-round iterations. On the aspect of iterative structure, instead of calculating sequentially, a parallel structure is designed. The improvement lies in the combination of two message blocks independently in each round. The statistical data and experimental analysis prove that the designed hash function algorithm has good properties of confusion and diffusion, collision resistance and superior efficiency, which can make it become a new type of candidate for hash function.