Data Authentication System Study Guide

Glossary

Term DefinitionsData UnitData such as electronic files, communications, documents, pictures, contracts, etc. that need to be authenticated.HashA one-way encryption function that converts data of any length into a fixed-length string, used to generate a unique identifier for data.BlockchainA distributed database that stores transaction records in a chain structure, with the characteristics of decentralization and immutability.Distributed LedgerA database that is shared, replicated, and synchronized between multiple nodes, and blockchain is one of its implementations.Cryptographic StructureA structure used to organize and store hash values, such as Merkle trees, Patricia trees, Tiger hash trees, etc.Merkle TreeA binary tree structure, where leaf nodes store hash values of data blocks, parent nodes store hash values of child nodes, and root nodes store hash values of the entire tree.Patricia TreeA data structure based on Trie trees, used to efficiently store and search for strings, also known as radix trees or compressed prefix trees. Tiger Hash Tree A Merkle tree variant that uses the Tiger hash function, used to verify the integrity of large files. Proof Contains credentials for verifying the information required to authenticate a data unit, such as a Merkle index, hash algorithm, timestamp, etc. OP_RETURN An opcode in the Bitcoin scripting language that allows a small amount of data to be embedded in a transaction, often used to anchor data to the blockchain.

Short answer questions

What is the role of a data unit authentication system?

The system uses blockchain or distributed ledger technology to provide authentication services for the existence, integrity, and ownership of data units such as electronic files and communications, similar to an electronic notary system.

How are data units associated with the blockchain?

The system hashes the data unit and stores the hash value in an encrypted structure, and eventually publishes the root hash value of the encrypted structure to the blockchain, thereby associating the data unit with the blockchain.

What is the role of the Merkle tree in data unit authentication?

As an encrypted structure, the Merkle tree can efficiently organize and store the hash values of data units and generate a unique root hash value to facilitate data integrity verification.

What key information does the proof contain?

The proof contains the name of the data unit, the time of authentication, notarization information, hash algorithm, Merkle index, transaction ID and other information, which is used to verify the authenticity and integrity of the data.

How to verify the authentication of the data unit?

The user can use the Merkle index provided in the proof to obtain the corresponding Merkle tree from the blockchain, and calculate the hash value of the data unit according to the same hash algorithm. Finally, the calculation result is compared with the corresponding hash value in the Merkle tree. If they are consistent, the authentication is passed.

Why is it said that this system can overcome the limitation of Bitcoin block size?

Bitcoin block size is limited, but the system can authenticate a large amount of data by storing the hash values of multiple data units in the Merkle tree and only publishing the root hash value to the blockchain.

What is the role of OP_RETURN in data unit authentication?

OP_RETURN is an opcode in the Bitcoin scripting language that allows a small amount of data to be embedded in a transaction. The system uses OP_RETURN to publish the root hash value of the Merkle tree to the Bitcoin blockchain.

What scenarios can this system be applied to?

The system can be used to notarize digital transactions, establish ownership of digital assets, create audit trails, and other scenarios.

What are the advantages of this system compared to traditional electronic notarization systems?

Compared with traditional electronic notarization systems, this system is based on decentralized blockchain technology, is more secure and reliable, and can process massive amounts of data at a lower cost.

What are the future development directions of this system?

In the future, the system can be integrated with more types of blockchain and distributed ledger technologies, and support more complex data structures and authentication processes to meet the growing demand for data authentication.