Hierarchical Multiparty Digital Signature for Distributed Systems: Application in Intelligent Vehicle Surveillance  
[PERSON]  
1 LIAP Laboratory, University of El Oued, P.O. Box 789, El Oued 39000, Algeria; [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (M.A.) [PERSON]  
1 LIAP Laboratory, University of El Oued, P.O. Box 789, El Oued 39000, Algeria; [EMAIL_ADDRESS] (S.G.); [EMAIL_ADDRESS] (M.A.) [PERSON]  
2 Interdisciplinary Research Center for Intelligent Secure Systems, KFUMP, Dhahran 31261, Saudi Arabia  
digital signatures ensure that the signers cannot later repudiate their signatures due to the mathematical linkage between the private key and the signed message. In asymmetric cryptography, digital signature techniques rely on private keys as a key element for their operation. The digital signature--uniquely derived from the data and the private key--serves as a tamper-proof identifier, ensuring that the data originate from the intended source and have not been altered during transmission. The signing process begins with the signer using their private key--a secret known only to them--to create the digital signature, which is then transmitted along with the signed data to the recipient. On the recipient's side, verification leverages the signer's public key, which is mathematically linked to the private key, thus making it computationally infeasible for an attacker to forge a signature without access to the private key. In the increasingly interconnected world of the Internet of Things (IoT) and distributed systems, the need for secure and reliable methods of authentication and data integrity has become paramount [2; 3; 4]. These systems often involve vast networks of devices, sensors, and stakeholders, making them particularly vulnerable to cyber attacks and data breaches. Traditional digital signature schemes, typically designed for single entities, are inadequate for addressing the complexities and vulnerabilities inherent in such environments. They fail to accommodate the collaborative nature of distributed systems, where multiple parties work together to authenticate transactions, validate messages, or reach consensus on critical decisions. Multiparty digital signature techniques have emerged as a robust solution to address these challenges. These schemes enable several participants to collaboratively generate a single, unified digital signature, which cryptographically secures the contributions and consent of all parties involved. This collaborative approach significantly enhances trust and accountability in distributed environments, as the resulting signature serves as a verifiable record of consensus among the stakeholders. By requiring the involvement of multiple parties, multiparty digital signatures provide an additional layer of security against unauthorized activities. Malicious entities would find it exceedingly difficult to forge or tamper with the signature without detection, as doing so would necessitate the compromising of multiple independent participants. In contrast to simply appending individual signatures after the message, this article presents a hierarchical multiparty digital signature (HMPS) technique tailored to the unique demands of IoT and distributed systems for public security. This layered aggregation approach offers several distinct advantages including scalability and efficiency; rather than transmitting and verifying a long list of individual signatures, the hierarchical scheme aggregates these into a compact signature. This reduces communication overheads and allows for batch verification, thereby enhancing computational efficiency--an essential feature in resource-constrained IoT environments. This approach has enhanced security; by organizing the signing process into multiple layers, the hierarchical approach minimizes the risk of a single point of failure. Even if one layer is compromised, the structure ensures that the integrity of the overall signature remains intact. This layered defense mechanism provides stronger resistance against forgery and unauthorized modifications.