New Blind Muti-signature Schemes based on ECDLP

In various types of electronic transactions, including election systems and digital cash schemes, user anonymity and authentication are always required. Blind signatures are considered the most important solutions to meeting these requirements. Many studies have focused on blind signature schemes; however, most of the studied schemes are single blind signature schemes. Although blind multi-signature schemes are available, few studies have focused on these schemes. In this article, blind multi-signature schemes are proposed based on the Elliptic Curve Discrete Logarithm Problem (ECDLP). The proposed schemes are based on the GOST R34.10-2012 digital signature standard and the EC-Schnorr digital signature scheme, and they satisfy blind multi-signature security requirements and have better computational performance than previously proposed schemes. The proposed schemes can be applied in election systems and digital cash schemes

Key Substitution in the Symbolic Analysis of Cryptographic Protocols (extended version)

Key substitution vulnerable signature schemes are signature schemes that permit an intruder, given a public verification key and a signed message, to compute a pair of signature and verification keys such that the message appears to be signed with the new signature key. A digital signature scheme is said to be vulnerable to destructive exclusive ownership property (DEO) If it is computationaly feasible for an intruder, given a public verification key and a pair of message and its valid signature relatively to the given public key, to compute a pair of signature and verification keys and a new message such that the given signature appears to be valid for the new message relatively to the new verification key. In this paper, we prove decidability of the insecurity problem of cryptographic protocols where the signature schemes employed in the concrete realisation have this two properties

Practical Certificateless Aggregate Signatures From Bilinear Maps

Aggregate signature is a digital signature with a striking property that anyone can aggregate n individual signatures on n different messages which are signed by n distinct signers, into a single compact signature to reduce computational and storage costs. In this work, two practical certificateless aggregate signature schemes are proposed from bilinear maps. The first scheme CAS-1 reduces the costs of communication and signer-side computation but trades off the storage, while CAS-2 minimizes the storage but sacrifices the communication costs. One can choose either of the schemes by consideration of the application requirement. Compare with ID-based schemes, our schemes do not entail public key certificates as well and achieve the trust level 3, which imply the frauds of the authority are detectable. Both of the schemes are proven secure in the random oracle model by assuming the intractability of the computational Diffie-Hellman problem over the groups with bilinear maps, where the forking lemma technique is avoided

Blind multi-signature scheme based on factoring and discrete logarithm problem

One of the important objectives of information security systems is providing authentication of the electronic documents and messages. In that, blind signature schemes are an important solution to protect the privacy of users in security electronic transactions by highlighting the anonymity of participating parties. Many studies have focused on blind signature schemes, however, most of the studied schemes are based on single computationally difficult problem. Also digital signature schemes from two difficult problems were proposed but the fact is that only finding solution to single hard problem then these digital signature schemes are breakable. In this paper, we propose a new signature schemes base on the combination of the RSA and Schnorr signature schemes which are based on two hard problems: IFP and DLP. Then expanding to propose a single blind signature scheme, a blind multi-signature scheme, which are based on new baseline schemes

PERFORMANCE OF HYBRID SIGNATURES FOR PUBLIC KEY INFRASTRUCTURE CERTIFICATES

The modern public key infrastructure (PKI) model relies on digital signature algorithms to provide message authentication, data integrity, and non-repudiation. To provide this, digital signature algorithms, like most cryptographic schemes, rely on a mathematical hardness assumption for provable security. As we transition into a post-quantum era, the hardness assumptions used by traditional digital signature algorithms are increasingly at risk of being solvable in polynomial time. This renders the entirety of public key cryptography, including digital signatures, vulnerable to being broken. Hybrid digital signature schemes represent a potential solution to this problem. In this thesis, we provide the first test implementation of true hybrid signature algorithms. We evaluate the viability and performance of several hybrid signature schemes against traditional hybridization techniques via standalone cryptographic operations. Finally, we explore how hybrid signatures can be integrated into existing X.509 digital certificates and examine their performance by integrating both into the Transport Layer Security 1.3 protocol.Outstanding ThesisGunnery Sergeant, United States Marine CorpsApproved for public release; distribution is unlimited

On the security of digital signature schemes based on error-correcting codes

We discuss the security of digital signature schemes based on error-correcting codes. Several attacks to the Xinmei scheme are surveyed, and some reasons given to explain why the Xinmei scheme failed, such as the linearity of the signature and the redundancy of public keys. Another weakness is found in the Alabbadi-Wicker scheme, which results in a universal forgery attack against it. This attack shows that the Alabbadi-Wicker scheme fails to implement the necessary property of a digital signature scheme: it is infeasible to find a false signature algorithm D from the public verification algorithm E such that E(D*(m)) = m for all messages m. Further analysis shows that this new weakness also applies to the Xinmei scheme

Novel one time signatures (NOTS) : a compact post-quantum digital signature scheme

The future of the hash based digital signature schemes appears to be very bright in the upcoming quantum era because of the quantum threats to the number theory based digital signature schemes. The Shor's algorithm is available to allow a sufficiently powerful quantum computer to break the building blocks of the number theory based signature schemes in a polynomial time. The hash based signature schemes being quite efficient and provably secure can fill in the gap effectively. However, a draw back of the hash based signature schemes is the larger key and signature sizes which can prove a barrier in their adoption by the space critical applications, like the blockchain. A hash based signature scheme is constructed using a one time signature (OTS) scheme. The underlying OTS scheme plays an important role in determining key and signature sizes of a hash based signature scheme. In this article, we have proposed a novel OTS scheme with minimized key and signature sizes as compared to all of the existing OTS schemes. Our proposed OTS scheme offers an 88% reduction in both key and signature sizes as compared to the popular Winternitz OTS scheme. Furthermore, our proposed OTS scheme offers an 84% and an 86% reductions in the signature and the key sizes respectively as compared to an existing compact variant of the WOTS scheme, i.e. WOTS +