7 results sorted by ID
Possible spell-corrected query: RSA parameters validation
2023/078
Last updated: 2023-06-23
An Efficient Multi-Signature Scheme for Blockchain
Mostefa Kara, Abdelkader Laouid, Mohammad Hammoudeh
Cryptographic protocols
Blockchain is a newly emerging technology, however, it has proven effective in many applications because it provides multiple advantages, mainly as it represents a trust system in which data is encrypted in a way that cannot be tampered with or forged. Because it contains many details such as smart contracts, consensus, authentication, etc. the blockchain is a fertile ground for researchers where they can continually improve previous versions of these concepts. This paper introduces a new...
Exponential Increment of RSA Attack Range via Lattice Based Cryptanalysis
Abderahmanne Nitaj, Muhammad Rezal Kamel Ariffin, Nurul Nur Hanisah Adenan, Domenica Stefania Merenda, Ali Ahmadian
Public-key cryptography
The RSA cryptosystem comprises of two important features that are needed for encryption process known as the public parameter $e$ and the modulus $N$. In 1999, a cryptanalysis on RSA which was described by Boneh and Durfee focused on the key equation $ed-k\phi(N)=1$ and $e$ of the same magnitude to $N$. Their method was applicable for the case of $d<N^{0.292}$ via Coppersmith’s technique. In 2012, Kumar et al. presented an improved Boneh-Durfee attack using the same equation which is valid...
New (k,l,m)-verifiable multi-secret sharing schemes based on XTR public key system
Jing Yang, Fang-Wei Fu
Cryptographic protocols
Secret sharing was proposed primarily in 1979 to solve the problem of key distribution. In recent decades, researchers have proposed many improvement schemes. Among all these schemes, the verifiable multi-secret sharing (VMSS) schemes are studied sufficiently, which share multiple secrets simultaneously and perceive malicious dealer as well as participants. By pointing out that the schemes presented by Dehkordi and Mashhadi in 2008 cannot detect some vicious behaviors of the dealer, we...
Raccoon Attack: Finding and Exploiting Most-Significant-Bit-Oracles in TLS-DH(E)
Robert Merget, Marcus Brinkmann, Nimrod Aviram, Juraj Somorovsky, Johannes Mittmann, Jörg Schwenk
Cryptographic protocols
Diffie-Hellman key exchange (DHKE) is a widely adopted method for exchanging cryptographic key material in realworld protocols like TLS-DH(E). Past attacks on TLS-DH(E) focused on weak parameter choices or missing parameter validation. The confidentiality of the computed DH share, the premaster secret, was never questioned; DHKE is used as a generic method to avoid the security pitfalls of TLS-RSA.
We show that due to a subtle issue in the key derivation of all TLS-DH(E) cipher suites in...
Hashing solutions instead of generating problems: On the interactive certification of RSA moduli
Benedikt Auerbach, Bertram Poettering
Public-key cryptography
Certain RSA-based protocols, for instance in the domain of group signatures, require a prover to convince a verifier that a set of RSA parameters is well-structured (e.g., that the modulus is the product of two distinct primes and that the exponent is co-prime to the group order). Various corresponding proof systems have been proposed in the past, with different levels of generality, efficiency, and interactivity.
This paper proposes two new proof systems for a wide set of properties that...
A Bounded-Space Near-Optimal Key Enumeration Algorithm for Multi-Dimensional Side-Channel Attacks
Liron David, Avishai Wool
Enumeration of cryptographic keys in order of likelihood based on side-channel leakages has a significant importance in cryptanalysis. Previous algorithms enumerate the keys in optimal order, however their space complexity is $\Omega(n^{d/2})$ when there are d subkeys and n candidate values per subkey. We propose a new key enumeration algorithm that has a space complexity bounded by $O(d^2 w+dn)$, when w is a design parameter, which allows the enumeration of many more keys without exceeding...
Practical Cryptanalysis of ISO/IEC 9796-2 and EMV Signatures
Jean-Sebastien Coron, David Naccache, Mehdi Tibouchi, Ralf-Philipp Weinmann
Public-key cryptography
In 1999, Coron, Naccache and Stern discovered an existential signature forgery for two popular RSA signature standards, ISO/IEC 9796-1 and 2. Following this attack ISO/IEC 9796-1 was withdrawn. ISO/IEC 9796-2 was amended by increasing the message digest to at least 160 bits. Attacking this amended version required at least 2^61 operations.
In this paper, we exhibit algorithmic refinements allowing to attack the amended (currently valid) version of ISO/IEC 9796-2 for all modulus sizes. A...
Blockchain is a newly emerging technology, however, it has proven effective in many applications because it provides multiple advantages, mainly as it represents a trust system in which data is encrypted in a way that cannot be tampered with or forged. Because it contains many details such as smart contracts, consensus, authentication, etc. the blockchain is a fertile ground for researchers where they can continually improve previous versions of these concepts. This paper introduces a new...
The RSA cryptosystem comprises of two important features that are needed for encryption process known as the public parameter $e$ and the modulus $N$. In 1999, a cryptanalysis on RSA which was described by Boneh and Durfee focused on the key equation $ed-k\phi(N)=1$ and $e$ of the same magnitude to $N$. Their method was applicable for the case of $d<N^{0.292}$ via Coppersmith’s technique. In 2012, Kumar et al. presented an improved Boneh-Durfee attack using the same equation which is valid...
Secret sharing was proposed primarily in 1979 to solve the problem of key distribution. In recent decades, researchers have proposed many improvement schemes. Among all these schemes, the verifiable multi-secret sharing (VMSS) schemes are studied sufficiently, which share multiple secrets simultaneously and perceive malicious dealer as well as participants. By pointing out that the schemes presented by Dehkordi and Mashhadi in 2008 cannot detect some vicious behaviors of the dealer, we...
Diffie-Hellman key exchange (DHKE) is a widely adopted method for exchanging cryptographic key material in realworld protocols like TLS-DH(E). Past attacks on TLS-DH(E) focused on weak parameter choices or missing parameter validation. The confidentiality of the computed DH share, the premaster secret, was never questioned; DHKE is used as a generic method to avoid the security pitfalls of TLS-RSA. We show that due to a subtle issue in the key derivation of all TLS-DH(E) cipher suites in...
Certain RSA-based protocols, for instance in the domain of group signatures, require a prover to convince a verifier that a set of RSA parameters is well-structured (e.g., that the modulus is the product of two distinct primes and that the exponent is co-prime to the group order). Various corresponding proof systems have been proposed in the past, with different levels of generality, efficiency, and interactivity. This paper proposes two new proof systems for a wide set of properties that...
Enumeration of cryptographic keys in order of likelihood based on side-channel leakages has a significant importance in cryptanalysis. Previous algorithms enumerate the keys in optimal order, however their space complexity is $\Omega(n^{d/2})$ when there are d subkeys and n candidate values per subkey. We propose a new key enumeration algorithm that has a space complexity bounded by $O(d^2 w+dn)$, when w is a design parameter, which allows the enumeration of many more keys without exceeding...
In 1999, Coron, Naccache and Stern discovered an existential signature forgery for two popular RSA signature standards, ISO/IEC 9796-1 and 2. Following this attack ISO/IEC 9796-1 was withdrawn. ISO/IEC 9796-2 was amended by increasing the message digest to at least 160 bits. Attacking this amended version required at least 2^61 operations. In this paper, we exhibit algorithmic refinements allowing to attack the amended (currently valid) version of ISO/IEC 9796-2 for all modulus sizes. A...