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

Key management for beyond 5G mobile small cells: a survey

The highly anticipated 5G network is projected to be introduced in 2020. 5G stakeholders are unanimous that densification of mobile networks is the way forward. The densification will be realized by means of small cell technology, and it is capable of providing coverage with a high data capacity. The EU-funded H2020-MSCA project “SECRET” introduced covering the urban landscape with mobile small cells, since these take advantages of the dynamic network topology and optimizes network services in a cost-effective fashion. By taking advantage of the device-to-device communications technology, large amounts of data can be transmitted over multiple hops and, therefore, offload the general network. However, this introduction of mobile small cells presents various security and privacy challenges. Cryptographic security solutions are capable of solving these as long as they are supported by a key management scheme. It is assumed that the network infrastructure and mobile devices from network users are unable to act as a centralized trust anchor since these are vulnerable targets to malicious attacks. Security must, therefore, be guaranteed by means of a key management scheme that decentralizes trust. Therefore, this paper surveys the state-of-the-art key management schemes proposed for similar network architectures (e.g., mobile ad hoc networks and ad hoc device-to-device networks) that decentralize trust. Furthermore, these key management schemes are evaluated for adaptability in a network of mobile small cells

Certificateless Blind Signature Based on DLP

The most widely used digital signature in the real word application such as e cash e-voting etc. is blind signature. Previously the proposed blind signature follow the foot steps of public key cryptography(PKC) but conventional public key cryptography uses an affirmation of a relationship between public key and identity for the holder of the corresponding private key to the user, so certificate management is very difficult. To overcome this problem Identity based cryptography is introduced. But Identity based cryptography is inherited with key escrow problem. Blind signature with certificateless PKC(CLBS) used widely because it eliminate the problem related to certificate management of cryptography and the key escrow problem of ID based PKC. Because of large requirement of CLBS scheme in different applications many CLBS scheme is proposed, but they were based on bilinear pairing. However, the CLBS scheme based on bilinear pairing is not very satisfiable because bilinear pairing operations are very complicated. In our proposed scheme, we designed a certificateless blind signature scheme based on the discrete logarithmic problem. The proposed scheme fulfills all the security requirements of blind signature as well as certificateless signature. We analyzed security properties such as blindness, unforgeability and unlinkability. The proposed scheme has less computational cost. The hardness of discrete logarithmic problem (DLP) is used to prove the security of the proposed scheme

Black-Box Constructions of Signature Schemes in the Bounded Leakage Setting

To simplify the certificate management procedures, Shamir introduced the concept of identity-based cryptography (IBC). However, the key escrow problem is inherent in IBC. To get rid of it, Al-Riyami and Paterson introduced in 2003 the notion of certificateless cryptography (CLC). However, if a cryptosystem is not perfectly implemented, adversaries would be able to obtain part of the system\u27s secret state via side-channel attacks, and thus may break the system. This is not considered in the security model of traditional cryptographic primitives. Leakage-resilient cryptography was then proposed to prevent adversaries from doing so. There are fruitful works on leakage-resilient encryption schemes, while there are not many on signature schemes in the leakage setting. In this work, we review the folklore generic constructions of identity-based signature and certificateless signature, and show that if the underlying primitives are leakage-resilient, so are the resulting identity-based signature scheme and certificateless signature scheme. The leakage rate follows the minimum one of the underlying primitives. We also show some instantiations of these generic constructions

A survey on wireless body area networks: architecture, security challenges and research opportunities.

In the era of communication technologies, wireless healthcare networks enable innovative applications to enhance the quality of patients’ lives, provide useful monitoring tools for caregivers, and allows timely intervention. However, due to the sensitive information within the Wireless Body Area Networks (WBANs), insecure data violates the patients’ privacy and may consequently lead to improper medical diagnosis and/or treatment. Achieving a high level of security and privacy in WBAN involves various challenges due to its resource limitations and critical applications. In this paper, a comprehensive survey of the WBAN technology is provided, with a particular focus on the security and privacy concerns along with their countermeasures, followed by proposed research directions and open issues

An Authenticated Key Agreement Scheme using Vector Decomposition

Encryption using vector decomposition problem (VDP) on higher dimensional vector spaces is a novel method in cryptography. Yoshida has shown that the VDP on a two-dimensional vector space is at least as hard as the computational Diffie-Hellman problem on a one-dimensional subspace under certain conditions. Steven Galbraith has shown that for certain curves, the VDP is at most as hard as the discrete logarithm problem on a one-dimensional subspace. Okomoto and Takashima proposed encryption scheme and signature schemes using VDP. An authenticated key agreement scheme using vector decomposition problem is proposed in this pape

A supplement to Liu et al.\u27s certificateless signcryption scheme in the standard model

Recently, Liu et al. proposed the first certificateless signcryption scheme without random oracles and proved it was semantically secure in the standard model. However, Selvi et al. launched a fatal attack to its confidentiality by replacing users\u27 public keys, thus pointed out this scheme actually doesn\u27t reach the semantic security as claimed. In this paper, we come up with a rescue scheme based on Liu et al.\u27s original proposal. A Schnorr-based one-time signature is added to each user\u27s public key, which is used to resist Selvi et al.\u27s attack. In addition, according to the mistake made in Liu et al.\u27s security proof, we also show that our improvement is really secure in the standard model under the intractability of the decisional bilinear Diffie-Hellman assumption

On security of a Certificateless Aggregate Signature Scheme

Aggregate signatures are useful in special areas where the signatures on many different messages generated by many different users need to be compressed. Recently, Xiong et al. proposed a certificateless aggregate signature scheme provably secure in the random oracle model under the Computational Diffie-Hellman assumption. Unfortunately, by giving concrete attacks, we indicate that Xiong et al. aggregate signature scheme does not meet the basic requirement of unforgeability

McCLS: Certificateless Signature Scheme for Emergency Mobile Wireless Cyber-Physical Systems

Mobile Ad Hoc Network is a self-configurable and self-organizing wireless network of mobile devices without fixed infrastructure support, which makes it a good candidate as underlying communication network for the Cyber-Physical Systems in emergency conditions such as earthquake, flood, and battlefields. In these scenarios, efficient communication schemes with security support are especially desired. Two cryptography approaches, the public key cryptography and the identitybased cryptography, face the costly and complex key management problem and the “key escrow" problem in the real-life deployment. Recently, the certificateless public key cryptography (CL-PKC) was introduced to address these problems in previous approaches. However, the efficiency of the schemes based on CL-PKC is not high and can be improved further. In this paper, we present an improved certificateless signature scheme (McCLS) based on bilinear pairings. First, we theoretically compare the efficiency of McCLS with that of existing certificateless signature schemes (CLS). Second, an empirical study is conducted to compare the traditional AODV with the McCLS scheme based on AODV (McDV) in their efficiency and effectiveness against two most common attacks (i.e. redirection attack and rushing attack). Results from theoretical analysis show that the new McCLS scheme is more efficient than existing CLS solutions, and results from empirical studies show that the McDV is able to resist the two common attacks without causing substantial degradation of the network performance

Efficient Certificateless Online/Offline Signature

Abstract Public key cryptography usually is computationally more expensive than symmetric key systems. Due to this low power or resource constrained devices cannot make use of public key cryptosystems easily. There is a need for high security in these devices since many of these devices perform complex tasks which includes interaction with third party cloud infrastructures. These cloud infrastructures are not trusted entities. Hence there is need for light weight public key cryptography which are secure against these cloud administrators. The trusted entity in certificateless schemes cannot compromise the security of the users. Online/offline have two parts, first the computationally heavy part(offline) of the cryptosystem and then the main "online" algorithm for use on resource constrained devices. The heavy computations are done in the offline phase on a more powerful device. Hence, Certificateless online/offline schemes are perfect for low power devices interacting with clouds. In this paper, we present a certificateless online/offline signature scheme. This scheme is the most efficient certificateless signature scheme in existence and also has the added advantage of being online/offline. The scheme is proven secure in the random oracle model