Certificateless Strong Designated Verifier Signature Scheme

Jakobsson et al. first proposed the notions of designated verifier signature (DVS) and an enhanced version, strong designated verifier signature (SDVS) that only the designated verifier can verify the signature's validity. Since then, many improved schemes and variants have been proposed. In 2005, Lipmaa et al. introduced a delegation-attack and proposed a corresponding security concept, namely non-delegatability, which means that both the signer and the designated verifier can not delegate signing right to a third party to generate a valid signature. In this paper, we present a stronger security notion for the SDVS schemes, full non-delegatability, which not only needs the non-delegatability of signing, but also requires that non-delegatability of verifying. And we also analyze some previous SDVS schemes and find that all of them are not secure under the new security notion. At last, we propose an improved SDVS scheme based on identity (ID-SDVS). The proposed scheme is provably secure under the new security notion in the random oracle model.

A strong designated verifier signature (SDVS) is a special variant of digital signatures, since it only allows a designated recipient to verify the signer’s signature. The transcript simulation property of such signatures also prohibits a designated verifier from arbitrarily transferring his/her conviction to any third party. When implemented in certificateless cryptosystems, a certificateless SDVS is unnecessary to manage public key certificates and deal with the key-escrow problem of conventional identity-based systems. In 2014, Shim pointed out a crucial security property called non-delegatability for SDVS schemes. This property states that anyone should not be able to generate a valid SDVS without obtaining either the signer’s or the verifier’s private key. In other worlds, a non-delegatable SDVS scheme must ensure that any malicious adversary cannot forge a valid signature even if he/she has gotten the shared secret value between a signer and an intended verifier. In this paper, we first demonstrate that a previously proposed efficient certificateless SDVS scheme is vulnerable to the delegatability attack and then further propose an improved variant.

Many ID-based strong designated verifier signature schemes have been proposed in recent years. However, most of them did not give the rigorous security proofs and did not satisfy the strong ness property that anyone except the designated verifier cannot check the validity of a designated verifier signature, In addition, considering some special applications, these schemes have larger data size of communication. To overcome those problems, exploiting message recovery techniques which are regarded as a useful method to shorten ID-based signatures' size, we put forward an efficient ID-based strong designated verifier signature schemes with message recovery and give its rigorous security proof in the random oracle model based on the hardness assumptions of the computational Bilinear Diffie-Hellman problem in this paper. To the best of our knowledge, it is the first ID-based strong designated verifier signature schemes with message recovery and rigorous security proofs. Due to its merits, it can be used in some special environments where the bandwidth is one of the main concerns, such as PDAs, cell phones, RFID etc.

Strong designated verifier signature (SDVS) provides secret authentication service to entities in a computing task. The primitive assures that an entity's signature is verified only by a designated service provider. It also assures that a transcript about a computing task can be produced by both the entity and its service provider independently. Then neither can prove to a third party that an entity is involved in a task. Currently, most SDVS schemes without random oracles have no strong unforgeability and privacy of signer's identity. This paper proposes a systematic method to design SDVS schemes without random oracles. It provides a basic scheme with unforgeability and non-transferability properties. Then provides it an SDVS scheme with strong unforgeability and privacy of signer's identity properties and based on standard assumptions. Finally, a more efficient SDVS scheme is shown based on a non-black box assumption.

Designated verifier signature (DVS) is a cryptographic primitive, which allows a signer to convince a designated verifier of the validity of a signed statement and prevents the verifier from convincing any third party about the signature. As a variant of DVS, strong DVS (SDVS), which exhibits perfect non-transferability, does not accommodate secure disavow ability (or non-repudiation). It makes a SDVS more like a message authentication code rather than a digital signature. In this situation, the signer has to bear the responsibility of some "forged" signatures produced by the designated verifier. Therefore, it's interesting to construct a strong DVS scheme with secure disavow ability. In this paper, we address this problem with a novel construction of a SDVS scheme with secure disavow ability. The new scheme utilizes a chameleon hash function and supports the signer to have a complete control of his signature. Our scheme achieves unforgeability, non-transferability and secure disavow ability. Comparisons show that the new scheme outperforms the existing one in terms of computational efficiency and signature length.

ABSTRACTStrong designated verifier signature (SDVS) makes it possible for a signer to convince a designated verifier that he or she has signed a message in such a way that the designated verifier cannot transfer the signature to any third party and no third party can even verify the validity of the signature. Recently, Kang et al. proposed an identity‐based SDVS (IBSDVS) scheme that is claimed to be unforgeable and strong. However, in this paper, we show that their scheme is actually forgeable, delegatable, and not strong. We then propose an improved efficient IBSDVS scheme with short signature size and provide formal security proofs based on the computational Diffie–Hellman assumption in the random oracle model. We also show that the performance of our scheme outperforms all the existing IBSDVS schemes known in the literature. Furthermore, we propose an extension of our scheme achieving the stronger notion of nondelegatability and provide formal security proofs. The extended scheme is also showed to achieve high efficiency and short signature size. Copyright © 2012 John Wiley & Sons, Ltd.

Lattice-based strong designated verifier signature with non-delegatability

A strong designated verifier signature scheme makes it possible for a signer to convince a designated verifier that she has signed a message in such a way that the designated verifier cannot transfer the signature to a third party, and no third party can even verify the validity of a designated verifier signature. In 2005, Lipmaa, Wang, and Bao identified a new essential security property, non delegatability, of designated verifier signature schemes. Briefly, in a non delegatability designated verifier signature scheme, neither a signer nor a designated verifier can delegate the signing rights to any third party without revealing their secret keys. However, this paper shows that four recently proposed strong designated verifier signature schemes are delegatable. These schemes do not satisfy non delegatability secure requirement of strong designated verifier signature schemes.

Compared with ordinary digital signature, the strong designated verifier signature (SDVS) scheme makes it possible for a signer to convince a designated verifier that he or she has signed a message in such a way that the designated verifier cannot transfer the signature to a third party. Recently, Bao et al. proposed two ID-based SDVS schemes by use of bilinear pairing. In this paper, we show both of these schemes are insecure against active attack, that is the attacker can forge signature without signer's private key. Combining with the Schnorr signature scheme, we also provide a new efficient ID-based designated verifier signature scheme.

In this paper, we propose an ID-based strong designated verifier signature (SDVS) over R-SIS assumption in the random model. We remove pre-image sampling function and Bonsai trees such complex structures used in previous lattice-based SDVS schemes. We only utilize simple rejection sampling to protect the security of our scheme. Hence, we will show our design has the shortest signature size comparing with existing lattice-based ID-based SDVS schemes. In addition, our scheme satisfies anonymity (privacy of signer’s identity) proved in existing schemes rarely, and it can resist side-channel attacks with uniform sampling.

Signcryption is a cryptographic technique that provides both confidentiality and authenticity of data during public transmission in many modern applications like Internet -of -Things (IoT), Wireless Sensor Networks (WSNs) etc. The functionalities of encryption and Signature can achieve simultaneously through the signcryption with lower computational cost and communication overheads than those of traditional sign-then-encrypt approach. Many signcryption schemes have been constructed by various researchers in different cryptographic frameworks. Certificateless cryptography is one of the recent public key cryptography which eliminates the key escrow problem and complex certificate management problemsin identity based cryptography and traditional public key cryptography respectively. Providing the security and efficiency in many modern applications including IoT and WSNs is a crucial task. In this paper, we proposed new signcryption scheme in certificateless cryptography. This scheme supports the property of public verifiability and is secure against various types of adversaries in the random oracle model with the assumption that the Computational Diffie-Hellman Problem (CDHP) and the Elliptic Curve Discrete Logarithmic Problems (ECDLP) are hard. Due to pairing-free environment the proposed scheme is computationally more efficient than the existing public verifiable signcryption schemes.

Strong designated verifier signature scheme (SDVS) is a unique kind of digital signature scheme that has numerous applications in the networking infrastructure of present and future generations. In recent years, Lee-Chang has put forward a strong designated verifier signature scheme and stated that their scheme is secure. In this paper we show that Lee-Chang’s scheme is not secure, and any combatant can forge their scheme unaware of the secret key of the original signer and suggest an improved scheme which solves the fraud attack problem by any adversary. We analyze our scheme and compared with the Lee-Chang’s scheme and show that our scheme is secure and meet the security feathers needed by SDVS.

SummaryStrong Designated Verifier Signature (SDVS) provides authentication for the signer and the verifier such that the signer is assured that what s/he has signed, is only verified by the designated verifier. Currently, the security of most of the SDVS schemes is based on hard problems in the number theory. As it is proved that all kinds of cryptosystems which are based on the number theory will not tolerate quantum attacks, here, an SDVS scheme based on hard problems in coding theory is presented. We have proved that the suggested scheme is unforgeable under a chosen message attack in Random Oracle Model. Copyright © 2016 John Wiley & Sons, Ltd.

We propose a new computational problem called the twin Diffie–Hellman problem. This problem is closely related to the usual (computational) Diffie–Hellman problem and can be used in many of the same cryptographic constructions that are based on the Diffie–Hellman problem. Moreover, the twin Diffie–Hellman problem is at least as hard as the ordinary Diffie–Hellman problem. However, we are able to show that the twin Diffie–Hellman problem remains hard, even in the presence of a decision oracle that recognizes solutions to the problem—this is a feature not enjoyed by the Diffie–Hellman problem, in general. Specifically, we show how to build a certain “trapdoor test” that allows us to effectively answer decision oracle queries for the twin Diffie–Hellman problem without knowing any of the corresponding discrete logarithms. Our new techniques have many applications. As one such application, we present a new variant of ElGamal encryption with very short ciphertexts, and with a very simple and tight security proof, in the random oracle model, under the assumption that the ordinary Diffie–Hellman problem is hard. We present several other applications as well, including a new variant of Diffie and Hellman’s non-interactive key exchange protocol; a new variant of Cramer–Shoup encryption, with a very simple proof in the standard model; a new variant of Boneh–Franklin identity-based encryption, with very short ciphertexts; a more robust version of a password-authenticated key exchange protocol of Abdalla and Pointcheval.

With the rapid miniaturization in sensor technology, ruddervator, arduino, and multi-rotor system, drone technology catches much attention of the researchers. It can be controlled remotely by a seated operator sitting to a powerful intelligence computer system (PICS) or an airborne control and command platform (AC2P). The two types of drones (reconnaissance and attacking) can communicate with each other and with the PICS or AC2P through wireless network channels referred to as Flying Ad Hoc Network or Unmanned Aerial Vehicular Network (FANET or UAVN). When the line of sight is broken, communication is mainly carried out through satellite using GPS (Global Positioning System) signals. Both GPS and UAVN/FANET use open network channels for data broadcasting, exposed to several threats, and its security is challenging for the researchers. Monitoring data transmission traffic, espionage, troop movement, border surveillance, searching and warfare battlefield phenomenon, etc., can auspiciously be achieved by developing a robust authentication scheme for IoD deployment military drone. Therefore, this research illustrates the designing of two separate protocols based on aggregate signature, identity, pairing cryptography, and Computational Diffie-Hellman Problem (CDHP) to guarantee data integrity, authorization, and confidentiality among drones and AC2P/PICS. The outdated data transmission flaw has also been tackled, which is frequently noted in prior protocols. The security of these protocols will formally be verified using a random oracle model (ROM), a real-or-random (ROR) model, and informally using pragmatic illustration and mathematical lemmas. Nonetheless, the performance analysis section will be executed using the algorithmic big-O notation. The results show that these protocols are verifiably protected in the Random Oracle Model (ROM) and Real-Or-Random (ROR) model using the CDHP.