What is Polygon ID?

Polygon ID is a set of tools for developers that can be used to facilitate trusted and secure relationships between apps and users. Developers can use Polygon ID to enable the exchange of verifiable credentials secured by cryptography and the blockchain. Polygon ID is designed for developers with a strong focus on privacy, decentralization and user data self-sovereignty.

Verifiable credentials are issued according to the W3C standards and signed cryptographically to guarantee they are tamper-proof. This is performed by Issuers, which are trusted organizations or companies. In the real world, this could include your government, university, or bank. In Web3, this could include KYC providers, oracles, DAOs, reputation services, etc.

For these Issuers, Polygon ID includes the Issuer Node, a self hosted API capable of creating these credentials.

Credentials are not created in the void. They are created when a user requests them to prove something. The user then has to request, collect and store the credential. This is done through an identity wallet. In the same way a crypto wallet holds your crypto private keys, an identity wallet holds your identity keys and your credentials.

For these identity wallets (and for crypto wallets willing to expand to hold identity keys and credentials), Polygon ID includes the Wallet SDK. The Wallet SDK can be used to develop mobile wallets that request, store and present credentials or proof of credentials (using zero-knowledge proofs). Polygon ID also includes a JavaScript SDK for developing web-based wallets, browser extensions and dApps.

Last but not least, these credentials are meant to give the user some “power” - the power to prove something about him/herself to a dApp or SmartContract (the Verifers of the credential).

The process is like a “question-answer” dialog. A dApp needs to verify that I’m older than 18 to give me access to some content, or a SmartContract needs to verify that I’m human and unique before giving me an airdrop. These Verifiers can “ask” my wallet these questions and my wallet will produce a valid answer using my credentials.

The entire process is highly resistant to tampering - thanks to the use of PKI (public key infrastructure) and blockchain, and privacy preserving - thanks to the use of zero knowledge proofs.

For the verification part of the process, Polygon ID includes the Verifier SDK and smart contracts for off-chain and on-chain verification. These libraries allow the Verifier to compose different queries (questions) without having to deal with the complexity of reconfiguring the underlying cryptography.

Resources:

https://0xpolygonid.github.io/tutorials/ 

https://polygon.technology/blog/introducing-polygon-id-zero-knowledge-own-your-identity-for-web3