Verifiable Delay Function and Its Blockchain-Related Application: A Survey

Area of Science:

• Cryptography and Computer Science
• Blockchain Technology and Distributed Systems

Background:

• Verifiable Delay Functions (VDFs) have gained significant research interest since their 2018 inception.
• VDFs offer widespread applications in blockchain research, including computational timestamping, public random beacons, resource-efficient blockchains, and data replication proofs.

Purpose of the Study:

• To introduce the concept of Verifiable Delay Functions (VDFs).
• To systematically summarize the various types and characteristics of VDFs.
• To explore the underlying security assumptions and cryptographic underpinnings of VDF construction.
• To present a post-quantum VDF utilizing super-singular isogeny.
• To consolidate the understanding of VDF applications within blockchain technology.

Main Methods:

• Categorization and description of VDF types: weak, incremental, decodable, and trapdoor VDFs.
• Analysis of VDF construction based on algebraic and structural security assumptions.
• Explanation of cryptographic security assumptions relevant to VDFs.
• Introduction of a novel post-quantum VDF construction leveraging super-singular isogeny.

Main Results:

• A comprehensive overview of VDF classifications and their defining features.
• Detailed explanation of security assumptions, including algebraic and structural types.
• Presentation of a post-quantum VDF, enhancing security against future quantum computing threats.
• A structured summary of VDF applications pertinent to blockchain systems.

Conclusions:

• VDFs are a foundational cryptographic primitive with diverse and impactful applications in blockchain.
• Understanding VDF types and security assumptions is crucial for their effective implementation.
• The development of post-quantum VDFs is essential for future-proofing blockchain security.
• This paper provides a valuable resource for researchers and practitioners in VDFs and blockchain technology.