Vehicular Ad-Hoc Networks (VANETs) enable secure, real-time communication among vehicles and roadside infrastructure, improving traffic safety and system efficiency. However, VANETs face significant security and performance challenges due to their dynamic topology, real-time constraints, and resource limitations. This paper presents a novel efficient lightweight authentication scheme in certificateless(ELAS-FG) setting for VANETs, utilizing Factor Graph-based (FG) communication models to optimize efficiency and scalability. The proposed scheme integrates conditional probability distributions and message-passing algorithms from factor graph theory with cryptographic primitives to reduce computational and communication overhead. Performance analysis demonstrates that our method achieves robust security guarantees, including mutual authentication, integrity, and resistance against replay and impersonation attacks, while maintaining low latency and minimal resource consumption. Comparative analysis with existing schemes highlights the superior efficiency and practicality of our approach for real-world VANET environments.

The concept of blockchain, widely known as virtual currencies, saw a massive surge in popularity in recent times. As far as the security of the blockchain is concerned, consensus algorithms play a vital role in the blockchain. Research has been done separately, or comparisons between a few of them have been presented previously. In this paper, we have discussed widely used consensus algorithms in the blockchain. The consensus protocols covered in this paper include PoW (Proof of Work), PoS (Proof of Stake), DPoS (Delegated Proof of Stake), PoET (Proof of Elapsed Time), PBFT (Practical Byzantine Fault Tolerance), and PoA (Proof of Authority). For each consensus, we have reviewed the properties, applications, and performance in the blockchain.

The article proposes an Online/Off-line Ring Signature Scheme in random oracle model. Security of the scheme relies on both Computational Diffie-Hellman and k-CAA problems. In Online/Off-line signature scheme. The proposed scheme is secure against Existential Unforgeability. It has Signer Ambiguity and robustness property where the misbehavior of the signer can be detected.

The article proposes a novel construction of sign-cryption scheme with provable security which is most suited to be implement on smart card. It is secure in random oracle model and the security relies on Decisional Bilinear Diffie-Hellmann Problem. The proposed scheme is secure against adaptive chosen ciphertext attack (indistiguishbility) and adaptive chosen message attack (unforgeability). The scheme have the security properties anonymity and forward security. Also it is inspired by zero-knowledge proof and is publicly verifiable. The scheme has applied for mutual authentication to authenticate identity of smart card's user and reader via Application protocol Data units. This can be achieved by the verification of the signature of the proposed scheme. Also the sensitive information are stored in the form of ciphertext in Read Only Memory of smart cards. These functions are performed in one logical step at a low computational cost.

This article proposes a novel construction of short Online/Off-line signature scheme with provable security in the random oracle model for wireless sensor network (WSN). Security of the proposed scheme relies on k-CAA Problem as well as Computational Diffie-Hellman problem and is resistant against chosen message attack. The scheme is suited for broadcast authentication and integrity of message exchanging between the sensor nodes. The process of generation of the signature is carried out in two phases online and off-line. The heavy computation is performed in off-line phase, i.e the base station. The actual signature will be generated in the sensor nodes. The authors assume that the online phase is more efficient. Here they have evaluated the size of the signature with respect to the size of the user's public key and compare with some current schemes. Also, the authors have evaluated the computational cost and time which shows the scheme is most suited to implement on sensor node.