A short certificateless aggregate signature against coalition attacks

Area of Science:

• Cryptography
• Information Security

Background:

• Certificateless aggregate signature (CLAS) schemes compress signatures for efficiency.
• Cheng et al. proposed an efficient CLAS scheme, but it contains security vulnerabilities.
• Existing CLAS schemes are crucial for resource-constrained environments, reducing signature length and computational load.

Purpose of the Study:

• To identify and address security flaws in Cheng et al.'s CLAS scheme.
• To propose an improved CLAS scheme resistant to internal coalition attacks.
• To enhance the efficiency and security of certificateless aggregate signature schemes.

Main Methods:

• Analysis of Cheng et al.'s CLAS scheme to identify vulnerabilities.
• Development of a novel CLAS scheme incorporating enhanced security features.
• Security proof of the improved scheme under the Computational Diffie-Hellman (CDH) assumption.
• Performance comparison with existing CLAS schemes.

Main Results:

• Cheng et al.'s CLAS scheme is vulnerable to coalition attacks by internal signers.
• The proposed improved CLAS scheme effectively resists internal coalition attacks.
• The new scheme generates very short aggregate signatures.
• Performance analysis indicates lower communication overhead and computation cost compared to related schemes.

Conclusions:

• The improved CLAS scheme offers enhanced security against coalition attacks.
• The proposed scheme provides significant efficiency gains in terms of signature length and computational cost.
• This work contributes a more secure and efficient CLAS solution for practical applications.