An efficient and secure attribute based signcryption scheme with LSSS access structure.

Area of Science:

• Cryptography and Information Security
• Computer Science

Background:

• Attribute-based encryption (ABE) and attribute-based signatures (ABS) offer flexible access control and authentication for data sharing.
• Implementing both ABE and ABS concurrently leads to significant computational overhead.
• Existing ABE schemes often rely on tree structures, necessitating frequent recursive algorithm calls.

Purpose of the Study:

• To propose an efficient and secure ciphertext-policy attribute-based signcryption (CP-ABE-ABS) scheme.
• To combine the functionalities of CP-ABE and ABS into a single, integrated cryptographic primitive.
• To reduce the computational burden associated with combined access control and authentication.

Main Methods:

• Developed a novel CP-ABE-ABS scheme integrating encryption and signature functionalities.
• Replaced traditional tree structures with a linear secret sharing scheme (LSSS).
• Conducted rigorous security and performance analyses to validate the scheme.

Main Results:

• The proposed scheme enables legal receivers to decrypt ciphertexts and verify signatures.
• The use of LSSS effectively avoids the performance degradation from recursive algorithms.
• Security and efficiency analyses confirm the scheme's robustness and improved performance.

Conclusions:

• The novel CP-ABE-ABS scheme successfully integrates encryption and signature functionalities.
• The scheme offers enhanced efficiency compared to traditional approaches by optimizing structure.
• This work provides a more practical solution for secure and efficient data sharing in distributed systems.