SECURE AND OPTIMIZED CLOUD AUTHENTICATION USING XMSS WITH HTM-BASED HYBRID CRYPTOGRAPHIC KEY MANAGEMENT

Abstract

With the rapid adoption of cloud computing services, ensuring secure, efficient, and scalable authentication mechanisms has become increasingly critical. Traditional cryptographic techniques are often vulnerable to emerging threats, especially quantum attacks and side-channel vulnerabilities. To address these challenges, post-quantum cryptographic algorithms and hardware-based optimizations are gaining momentum. Conventional authentication methods in cloud environments often fail to ensure forward security, resistance to quantum-level threats, and protection against side-channel attacks. The lack of isolation during cryptographic execution further exposes private keys and signature schemes to timing and leakage attacks. This study introduces an enhanced cloud authentication model that integrates the eXtended Merkle Signature Scheme (XMSS), a hash-based, forward-secure, and post-quantum resistant signature scheme, with Hardware Transactional Memory (HTM). XMSS guarantees quantum-resistant authentication, while HTM ensures secure execution by isolating sensitive cryptographic operations in protected hardware regions. The system further employs hybrid cryptographic key algorithms to optimize the processes of key generation, signing, verification, and key storage. The HTM engine assists in minimizing leakage and enhancing efficiency, enabling secure communication between cloud users and service providers. Simulation results show a substantial improvement in key verification speed, signature integrity, and resistance to quantum and side-channel attacks. Compared to existing schemes such as RSA, ECC, and SPHINCS+, the proposed method offers a 30–40% performance boost in security-sensitive operations, with a reduced risk of cryptographic key exposure and computational overhead.