Search

Lattice attacks can compromise the security of encryption algorithms used in blockchain networks, allowing attackers to tamper with transaction records, steal private keys, and execute other forms of attacks. With symmetric encryption, both parties can encrypt and decrypt messages using the same key. Lattice attacks on digital signature algorithms (ECDSA) involve forming a basis and setting a target vector from signatures, then solving the closest vector problem (CVP) or shortest vector problem (SVP) in the generated lattice to obtain the private key. Prior research focused on obtaining leakage information from the signature's random nonce to facilitate a CVP or SVP solution. This study establishes a clear boundary for a successful ECDSA attack and introduces a "double basis" lattice version that expands the boundary or reduces the necessary signatures by nearly half with the same lattice rank. To approach the boundary, a heuristic strategy is employed to shift the target vector in different directions with a feasible step size, using tests on the Trusted Platform Module (TPM) 2.0 ECDSA. The distance from the closest moved target vector to the boundary is reduced by a ratio of 424 to 179 to the minimal length of orthogonal vectors in the formed basis. Experimental results show that moving attempts in two directions with the original basis and 84 signatures take approximately 247.7 s on the experiment computer. [ABSTRACT FROM AUTHOR]

Although digital signature has been a fundamental technology for cryptosystems, it still draws considerable attention from both academia and industry due to the recent raising interest in blockchains. This article revisits the subliminal channel existing digital signature and reviews its abuse risk of the constructor's private key. From a different perspective on the subliminal channel, we find the new concept named the chamber of secrets in blockchains. The found concept, whereby the secret is hidden and later recovered by the constructor from the common transactions in a blockchain, highlights a new way to encourage implementing various applications to benefit efficiency and security. Thus, the proposed scheme benefits from the following advantages: (1) avoiding the high maintenance cost of certificate chain of certificate authority, or public key infrastructure, and (2) seamlessly integrating with blockchains using the property of chamber of secrets. In order to easily understand the superiority of this new concept, a remote authentication scenario is taken as a paradigm of IoT to demonstrate that the further advantages are achieved: (1) avoiding high demand for storage space in IoT devices, and (2) avoiding maintaining a sensitive table in IoT server. [ABSTRACT FROM AUTHOR]