Confidentiality, Privacy and Ownership in Blockchain

Confidentiality, Privacy and Ownership in Blockchain

Key Terms

Term DefinitionsDigital Asset (Digital Identity Asset)Digital information about a user that identifies the user, such as the user's financial information, personal information, consumer information, etc. Identity ProviderThe entity that creates and stores the user's digital identity assets, such as a bank, employer, etc. Identity ConsumerThe entity that needs to access and use the user's digital identity assets, such as a bank, employer, etc. BlockchainA decentralized and immutable digital ledger that stores transaction data in chronological order. Smart ContractA code that is stored on the blockchain and automatically executes when certain conditions are met. Zero-knowledge proofA cryptographic method that allows one party (the prover) to prove to another party (the verifier) ​​that a statement is true without revealing any information other than the truth of the statement. Commitment SchemeA cryptographic technique that allows one party to commit to a value without revealing the value and later unwrap the commitment to reveal the value. Merkle Hash TreeA data structure used to efficiently verify the integrity of large data sets. AnonymityThe property that the identities of the parties involved in a transaction remain unknown. UnlinkabilityThe property that multiple transactions by the same user cannot be linked to each other. Short Answer Questions

What are the main threats to digital identity assets?

Digital identity assets face three main threats: identity providers and identity consumers may collude to exchange users' identity assets without the user's knowledge; identity providers and malicious users may collude to impersonate real users; users and malicious identity consumers may collude to claim and trade identity assets without the real identity provider.

How does blockchain technology help protect digital identity assets?

Blockchain technology helps protect digital identity assets by providing a decentralized, transparent and tamper-proof record of transactions. This eliminates the need for a trusted third party and ensures the verifiability and auditability of all transactions.

What is zero-knowledge proof and how is it used in digital identity asset exchanges?

Zero-knowledge proof allows one party to prove to another that it knows a secret without revealing any other information. In digital identity asset exchanges, zero-knowledge proofs allow users to prove to identity consumers that they own identity assets without revealing their identities or the contents of the identity assets.

What is the purpose of the ownership claim phase?

The purpose of the ownership claim phase is to bind the identities of the identity provider and the user to the identity asset without revealing their real identity. This is achieved by creating a combined cryptographic commitment that contains a commitment to the public keys of the identity provider and the user and the hash value of the identity asset.

How does the non-repetitive verification phase work?

The non-repetitive verification phase ensures unique ownership claims of identity assets by using a polynomial whose coefficients represent the cryptographic hash of previously claimed identity assets. The blockchain network verifies whether the new ownership claim conflicts with the existing claim.

How does the proof of ownership phase prevent malicious users from impersonating real users?

The proof of ownership phase requires the identity provider and user to provide cryptographic proof that they own the private key corresponding to the public key promised in the ownership claim. This ensures that only the genuine identity provider and user can transfer identity assets.

How do identity providers and identity consumers remain anonymous in this system?

Identity providers and identity consumers use pseudonyms to interact in place of their real identities. All transactions are recorded anonymously on the blockchain network, preventing the real identity of either party from being revealed.

Why is unlinkability a necessary property for the exchange of digital identity assets?

Unlinkability prevents profiling and tracking of users. If transactions are linkable, malicious parties can track the transaction history of users, even if the transactions were conducted anonymously.

What is the purpose of the cryptographic commitment scheme used in this invention?

Cryptographic commitment schemes allow parties to commit to a value without revealing the actual value, and later open that commitment to reveal the value. This is used in the ownership claim phase to hide the true identity of the identity provider, user, and identity asset, while still allowing ownership to be verified.

How does a Merkle hash tree enhance the security of this system?

Merkle hash trees are used to efficiently verify the integrity of ownership claims stored on the blockchain. This ensures that ownership claims cannot be tampered with without affecting the integrity of the entire blockchain.

Paper topic

Discuss the importance of anonymity and unlinkability in digital identity management. Describe how the present invention achieves these properties.

Explain the ownership claim, non-repetitive verification, and proof of ownership phases in detail. How does each phase help protect the ownership of digital identity assets?

Analyze the advantages and disadvantages of using blockchain technology for digital identity asset exchange. What advantages does it offer over traditional identity management systems?

Describe potential attack vectors that the present invention may face. Discuss what additional measures can be implemented to further enhance the security of the system.

Explore use cases for integrating the present invention into different industries such as finance, healthcare, and government. Discuss the potential advantages and challenges of such integrations.