A code based hybrid signcryption scheme

A key encapsulation mechanism (KEM) that takes as input an arbitrary string, i.e., a tag, is known as tag-KEM, while a scheme that combines signature and encryption is called signcryption. In this paper, we present a code-based signcryption tag-KEM scheme. We utilize a code-based signature and a CCA2 (adaptive chosen ciphertext attack) secure version of McEliece's {encryption} scheme. The proposed scheme uses an equivalent subcode as a public code for the receiver, making the NP-completeness of the equivalent subcode problem be one of our main security assumptions. We then base the signcryption tag-KEM to design a code-based hybrid signcryption scheme. A hybrid scheme deploys an asymmetric- as well as a symmetric-key encryption. We give security analyses of both our schemes in the standard model and prove that they are secure against IND-CCA2 (indistinguishability under adaptive chosen ciphertext attack) and SUF-CMA (strong existential unforgeability under chosen message attack).

A code based hybrid signcryption scheme

A key encapsulation mechanism (KEM) that takes as input an arbitrary string, i.e., a tag, is known as tag-KEM, while a scheme that combines signature and encryption is called signcryption. In this paper, we present a code-based signcryption tag-KEM scheme. We utilize a code-based signature and a CCA2 (adaptive chosen ciphertext attack) secure version of McEliece's {encryption} scheme. The proposed scheme uses an equivalent subcode as a public code for the receiver, making the NP-completeness of the equivalent subcode problem be one of our main security assumptions. We then base the signcryption tag-KEM to design a code-based hybrid signcryption scheme. A hybrid scheme deploys an asymmetric- as well as a symmetric-key encryption. We give security analyses of both our schemes in the standard model and prove that they are secure against IND-CCA2 (indistinguishability under adaptive chosen ciphertext attack) and SUF-CMA (strong existential unforgeability under chosen message attack).

Digital signature schemes with strong existential unforgeability

Digital signature schemes (DSS) are ubiquitously used for public authentication in the infrastructure of the internet, in addition to their use as a cryptographic tool to construct even more sophisticated schemes such as those that are identity-based. The security of DSS is analyzed through the existential unforgeability under chosen message attack (EUF-CMA) experiment which promises unforgeability of signatures on new messages even when the attacker has access to an arbitrary set of messages and their corresponding signatures. However, the EUF-CMA model does not account for attacks such as an attacker forging a different signature on an existing message, even though the attack could be devastating in the real world and constitutes a severe breach of the security system. Nonetheless, most of the DSS are not analyzed in this security model, which possibly makes them vulnerable to such an attack. In contrast, a better security notion known as strong EUF-CMA (sEUF-CMA) is designed to be resistant to such attacks. This review aims to identify DSS in the literature that are secure in the sEUF-CMA model. In addition, the article discusses the challenges and future directions of DSS. In our review, we consider the security of existing DSS that fit our criterion in the sEUF-CMA model; our criterion is simple as we only require the DSS to be at least secure against the minimum of existential forgery. Our findings are categorized into two classes: the direct and indirect classes of sEUF-CMA. The former is inherently sEUF-CMA without any modification while the latter requires some transformation. Our comprehensive review contributes to the security and cryptographic research community by discussing the efficiency and security of DSS that are sEUF-CMA, which aids in selecting robust DSS in future design considerations.

ID-based key-insulated signcryption with equality test in cloud computing

Key-insulated encryption reduces the problem of secret key exposure in hostile setting while signcryption cryptosystem attains the benefits of digitally signing a ciphertext and public key cryptosystem. In this study, we merge the primitives of parallel key-insulation cryptosystem and signcryption with equality test to construct ID-based parallel key-insulated signcryption with a test for equality (ID-PKSET) in cloud computing. The construction prevent data forgery, data re-play attacks and reduces the leakage of secret keys in harsh environments. Our scheme attains the security property of existential unforgeable chosen message attack (EUF-CMA) and indistinquishable identity chosen ciphertext attack (IND-ID-CCA2) using random oracle model.

A Fully Adaptively Secure Threshold Signature Scheme Based on Dual-Form Signatures Technology

In t , n threshold signature schemes, any subset of t participants out of n can produce a valid signature, but any fewer than t participants cannot. Meanwhile, a threshold signature scheme should remain robust and unforgeable against up to t − 1 corrupted participants. This nonforgeability property is that even an adversary breaking into up to t − 1 participants should be unable to generate signatures on its own. Existential unforgeability against adaptive chosen message attacks is widely considered as a standard security notion for digital signature, and threshold signature should also follow this accordingly. However, there are two special attack models in a threshold signature scheme: one is the static corruption attack and the other is the adaptive corruption attack. Since the adaptive corruption model appears to better capture real threats, designing and proving threshold signature schemes secure in the adaptive corruption model has been focused on in recent years. If a threshold signature is secure under adaptive chosen message attack and adaptive corruption attack, we say it is fully adaptively secure. In this paper, based on the dual pairing vector spaces technology, we construct a threshold signature scheme and use Gerbush et al.’s dual-form signatures technology to prove our scheme, which is fully adaptively secure in the standard model, and then compare it to other schemes in terms of the efficiency and computation.

Towards Green Computing Oriented Security: A Lightweight Postquantum Signature for IoE

Postquantum cryptography for elevating security against attacks by quantum computers in the Internet of Everything (IoE) is still in its infancy. Most postquantum based cryptosystems have longer keys and signature sizes and require more computations that span several orders of magnitude in energy consumption and computation time, hence the sizes of the keys and signature are considered as another aspect of security by green design. To address these issues, the security solutions should migrate to the advanced and potent methods for protection against quantum attacks and offer energy efficient and faster cryptocomputations. In this context, a novel security framework Lightweight Postquantum ID-based Signature (LPQS) for secure communication in the IoE environment is presented. The proposed LPQS framework incorporates a supersingular isogeny curve to present a digital signature with small key sizes which is quantum-resistant. To reduce the size of the keys, compressed curves are used and the validation of the signature depends on the commutative property of the curves. The unforgeability of LPQS under an adaptively chosen message attack is proved. Security analysis and the experimental validation of LPQS are performed under a realistic software simulation environment to assess its lightweight performance considering embedded nodes. It is evident that the size of keys and the signature of LPQS is smaller than that of existing signature-based postquantum security techniques for IoE. It is robust in the postquantum environment and efficient in terms of energy and computations.

Xây dựng lược đồ chữ ký số an toàn từ các lược đồ định danh

Tóm tắt— Trong tài liệu [3], khi trình bày về phương pháp xây dựng lược đồ chữ ký số dựa trên các lược đồ định danh chính tắc nhờ phép biến đổi Fiat-Shamir, tác giả đã chỉ ra “điều kiện đủ” để nhận được một lược đồ chữ ký số an toàn dưới tấn công sử dụng thông điệp được lựa chọn thích nghi là lược đồ định danh chính tắc phải an toàn dưới tấn công bị động. Tuy nhiên, tác giả của [3] chưa chỉ ra “điều kiện cần” đối với các lược đồ định danh chính tắc nhằm đảm bảo tính an toàn cho lược đồ chữ ký số được xây dựng. Do đó, trong bài báo này, chúng tôi hoàn thiện kết quả của [3] bằng việc chỉ ra điều kiện đủ đó cũng chính là điều kiện cần.Abstract— In [3], the author shows that, in order to the digital signature scheme Π' resulting from the Fiat-Shamir transform applied to a canonical identification scheme Π is existentially unforgeable under chosen-message attack then a “sufficient” condition is that the scheme Π has to be secure against a passive attack. However, the author of [3] has not shown the “necessary” conditions for the canonical identification schemes to ensure security of the digital signature scheme Π'. In this paper, we complete this result by showing that sufficient condition is also necessary.

Post quantum proxy signature scheme based on the multivariate public key cryptographic signature

Proxy signature is a very useful technique which allows the original signer to delegate the signing capability to a proxy signer to perform the signing operation. It finds wide applications especially in the distributed environment where the entities such as the wireless sensors are short of computational power and needed to be convinced to the authenticity of the server. Due to less proxy signature schemes in the post-quantum cryptography aspect, in this article, we investigate the proxy signature in the post-quantum setting so that it can resist against the potential attacks from the quantum adversaries. A general multivariate public key cryptographic proxy scheme based on a multivariate public key cryptographic signature scheme is proposed, and a heuristic security proof is given for our general construction. We show that the construction can reach Existential Unforgeability under an Adaptive Chosen Message Attack with Proxy Key Exposure assuming that the underlying signature is Existential Unforgeability under an Adaptive Chosen Message Attack. We then use our general scheme to construct practical proxy signature schemes for three well-known and promising multivariate public key cryptographic signature schemes. We implement our schemes and compare with several previous constructions to show our efficiency advantage, which further indicates the potential application prospect in the distributed network environment.

SPCACF: Secured Privacy-Conserving Authentication Scheme using Cuckoo Filter in VANET

Providing security for vehicular communication is essential since the network is vulnerable to severe attacks.The message authentication between vehicles and pavement units are essential for the purpose of security. Messages that passed between the vehicles should be encrypted and verified before the vehicle nodes could be trusted. The original identity of nodes can only be traceable by authorized parties and should not be exposed at any cause. However authentication between vehicles during message transformation does not guarantees message authentication rate accurately. To address these issues, the SPCACF scheme is proposed which is based on software devoid of relying on any particular hardware. Binary search algorithm is added in partial with Cuckoo Filter to achieve higher accomplishment than the preceding schemes in the batch wise verification phase. In order to guarantee that it can assure message authentication constraint, existential enforceability of underlying signature against adaptively chosen-message attack is proved under the positive filter pool method.