Extended security arguments for signature schemes

2019

A new hash-based, server-supported digital signature scheme was proposed recently in [13]. We decompose the concept into forwardresistant tags and a generic cryptographic time-stamping service. Based on the decomposition, we propose more tag constructions which allow efficient digital signature schemes with interesting properties to be built. In particular, the new schemes are more suitable for use in personal signing devices, such as smart cards, which are used infrequently. We define the forward-resistant tags formally and prove that (1) the discussed constructs are indeed tags and (2) combining such tags with time-stamping services gives us signature schemes.

Journal of Cryptology, 2009

This paper provides either security proofs or attacks for a large number of identity-based identification and signature schemes defined either explicitly or implicitly in existing literature. Underlying these is a framework that on the one hand helps explain how these schemes are derived, and on the other hand enables modular security analyses, thereby helping to understand, simplify and unify previous work. We also analyze a generic folklore construction that in particular yields identity-based identification and signature schemes without random oracles.

2006

It has been demonstrated by Bellare, Neven, and Namprempre (Eurocrypt 2004) that identity-based signature schemes can be constructed from any PKI-based signature scheme. In this paper we consider the following natural extension: is there a generic construction of “identity-based signature schemes with additional properties” (such as identity-based blind signatures, verifiably encrypted signatures, ...) from PKI-based signature schemes with the same properties? Our results show that this is possible for great number of properties including proxy signatures; (partially) blind signatures; verifiably encrypted signatures; undeniable signatures; forward-secure signatures; (strongly) key insulated signatures; online/offline signatures; threshold signatures; and (with some limitations) aggregate signatures. Using well-known results for PKI-based schemes, we conclude that such identity-based signature schemes with additional properties can be constructed, enjoying some better properties than specific schemes proposed until know. In particular, our work implies the existence of identity-based signatures with additional properties that are provably secure in the standard model, do not need bilinear pairings, or can be based on general assumptions.

Wseas Transactions on Computer Research, 2006

Since the introduction of the first concept of the digital signature scheme using public key cryptography various characteristics are added and many original algorithms are raised. In addition to this grow, a new concept in identification methods using public key algorithms is also introduced, that is zero knowledge protocol. Also, besides this development several significant methods for example the Fiat-Shamir method are established. The Fiat-Shamir scheme is based on a special type of digital signature scheme specifically RSA algorithm, this creates signature for its own, which is defenseless compared with the digital signature established via the RSA scheme. The zero knowledge protocol proofs rights of the digital signature on publicly known messages. The objective of this paper is to introduce an efficient concept in digital signature schemes using computational delegation and is believed to be more efficient than the existing methods.

A transitive signature scheme allows a signer to publish a graph in an authenticated and cost-saving manner. The resulting authenticated graph is indeed the transitive closure of the graph constructed by edges which are explicitly signed by the signer. A property of the transitive signature scheme enables such scenario is called composability which means that by knowing signatures on two edges of a triangle, one can infer to a valid signature on the other edge of the triangle without knowledge of the signer's secret key thereby saving the signer from signing one sig- nature. Several transitive signature schemes have been proposed so far (1{3). Their security assumptions are based on the intractability of computing discrete logarithm, inverting RSA function, factoring and solving Di-e-Hellman problem. In this paper, we will present another transitive signature scheme based the Guillou-Quisquater (GQ for short) signature scheme. The security of our proposed can be proven under th...

An Introduction to Digital Signature Schemes, 2010

Today, all types of digital signature schemes emphasis on secure and best verification methods. Different digital signature schemes are used in order for the websites, security organizations, banks and so on to verify user’s validity. Digital signature schemes are categorized to several types such as proxy, on-time, batch and so on. In this paper, different types of schemes are compared based on security level, efficiency, difficulty of algorithm and so on. Results show that best scheme depends on security, complexity and other important parameters. We tried simply to define the schemes and review them in practice.

2009

The use of concatenated Schnorr signatures [Sch91] for the hierarchical delegation of public keys is a well-known technique. In this paper we carry out a thorough analysis of the identity-based signature scheme that this technique yields. The resulting scheme is of interest since it is intuitive, simple and does not require pairings. We prove that the scheme is secure against existential forgery on adaptive chosen message and adaptive identity attacks using a variant of the Forking Lemma [PS00]. The security is proven in the Random Oracle Model under the discrete logarithm assumption. Next, we provide an estimation of its performance, including a comparison with the state of the art on identity-based signatures. We draw the conclusion that the Schnorrlike identity-based signature scheme is arguably the most efficient such scheme known to date.

2008

In this paper, we propose a new signature scheme that is existentially unforgeable under a chosen message attack without random oracle. The security of our scheme depends on a new complexity assumption called the k+1 square roots assumption. We also discuss the relationship between the k+1 square roots assumption and some related problems and provide some conjectures. Moreover, the k+1 square roots assumption can be used to construct shorter signatures under the random oracle model. As some applications, a new chameleon hash signature scheme and a on-line/off-line signature scheme and a new efficient anonymous credential scheme based on the proposed signature scheme are presented.

Proceedings of the 5th International Conference on Information Systems Security and Privacy, 2019

In this paper, we derive code-based signature schemes using Fiat-Shamir transformation on code-based zeroknowledge identification schemes, namely the Stern scheme, the Jain-Krenn-Pietrzak-Tentes scheme, and the Cayrel-Veron-El Yousfi scheme. We analyze the security of these code-based signature schemes and derive the security parameters to achieve the 128-bit level security. Furthermore, we implement these signature schemes and compare their performance on a PC.

RSA is a popular public key cryptology for encryption and signing messages. In 2008, Harn and Ren introduced a new identity-based RSA multi-signature scheme by adopting Shamir's signature scheme. But, we find that there are some flaws in their proposal: First, the original signer's signing secret key can be derived. Second, the verification equation will never hold even if the received signature and message are legal. Third, transmission environments are not taken into consideration. This manuscript will thoroughly make discussions on Harn and Ren's scheme by showing the mentioned flaws.

IACR Cryptol. ePrint Arch., 2019

Code-based cryptographic schemes recently raised to prominence as quantum-safe alternatives to the currently employed numbertheoretic constructions, which do not resist quantum attacks. In this article, we discuss the Courtois-Finiasz-Sendrier signature scheme and derive code-based signature schemes using the Fiat-Shamir transformation from code-based zero-knowledge identification schemes, namely the Stern scheme, the Jain-Krenn-Pietrzak-Tentes scheme, and the CayrelVeron-El Yousfi scheme. We analyze the security of these code-based signature schemes and derive the security parameters to achieve the 80bit and 128-bit level of classical security. To derive the secure parameters, we have studied the hardness of Syndrome Decoding Problem. Furthermore, we implement the signature schemes, based on the Fiat-Shamir transform, which were mentioned above, and compare their performance on a PC.

IET Information Security, 2009

We give a generic construction for universal designated-verifier signature schemes from a large class, C, of signature schemes. The resulting schemes are efficient and have two important properties. Firstly, they are provably DV-unforgeable, non-transferable and also non-delegatable. Secondly, the signer and the designated verifier can independently choose their cryptographic settings. We also propose a generic construction for identity-based signature schemes from any signature scheme in C and prove that the construction is secure against adaptive chosen message and identity attacks. We discuss possible extensions of our constructions to hierarchical identity-based signatures, identity-based universal designated verifier signatures, and identitybased ring signatures from any signature in C.

DEStech Transactions on Engineering and Technology Research, 2017

In this paper, we propose a new assumption, i.e., computation linear assumption, then we provide a new identity-based signature algorithm based on this assumption, use the bilinear pairings technique. We proof the security of this scheme based on the computation linear assumption. The scheme is proposed under the standard model. as well, the task is to output 1 2 3 ( ) 1 CLIN can be view as a computation "version" of decisional Linear assumption (DLIN) proposed by Boneh, Boyen, and Shacham [5]. DLIN can be briefly described as: given 1 2 , , , , c c g f v g f , where , , g f v is a group generator of prime order group  . The task is to distinguish the value 1 2 c c v  from a random element in  . Identity-Based Encryption (IBE), which has been firstly presented by Shamir [6], is an influential paradigm for embedding identity information into the encrypted data. In IBE, a message can be encrypted in terms of one's identity, and only the user who retain the private key corresponded to the very identity the message encrypted on can recover the ciphertext correctly. However, Shamir did not give out a practical scheme about IBE. An efficient and secure IBE construction leaves to be an open problem until the emergence of the work from Boneh and Franklin [2] and Cock . After that, many types of IBEs are proposed to adapt all kinds of scenarios: such as IBE that without random oracle [8][9]. IBE gives rise to the appearance of a brand new cryptography primitive: which is called identitybased signature (IBS). IBS enables the user, who holds a private key corresponded with a special identity, to generate a valid signature based on a message that, everyone who knows the public parameter, can verify the correctness of the signature. Boneh and Franklin proposed the first '

2004

This paper first positively answers the previously open question of whether it was possible to obtain an optimal security reduction for an identity based signature (IBS) under a reasonable computational assumption. We revisit the Sakai-Ogishi-Kasahara IBS that was recently proven secure by Bellare, Namprempre and Neven through a general framework applying to a large family of schemes. We show that

Lecture Notes in Computer Science, 2011

Since the discovery of identity based cryptography, a number of identity based signature schemes were reported in the literature. Although, a lot of identity based signature schemes were proposed, the only identity based deterministic signature scheme was given by Javier Herranz. This signature scheme uses Schnorr signature scheme for generating the private key of the users and uses BLS short signature scheme for generating users signature. The security of this scheme was proved in the random oracle model using forking lemma. In this paper, we introduce a new identity based deterministic signature scheme and prove the security of the scheme in the random oracle model, without the aid of forking lemma. Hence, our scheme offers tighter security reduction to the underlying hard problem than the existing identity based deterministic signature scheme.