APIs

0. Generete Custodial Wallet for an issuer (optional / FLOW only)

API Example Input:

email: abc@gmail.com
password: ****

Generates a private, public key pair in MongoDB. (custodial wallet) Output:

Successful, 200

1. API for Signing up an issuer

API Example Input:

public_key: <string>

Saves the Issuer with metadta in MongoDB. (public key, signature) Output:

encryptedPassword: <string>

2. API for Integrating Sign Up Button on 3rd party app

API Example Input:

public_key: <string>,
signature: <string>

Checks in MongoDB for if Issuer exists, after validating the signature Output:

qr: <qr code image> (public key encoded, metadata to invoke callback ZK server to save the requested args received) 

3. ZK Server API, for Integrating Sign Up Button on 3rd party app

On ZK Phone,

API Example Input:

qr: <image> (public key encoded, metadata has callback url which calls ZK server to save the requested args received and encryptedPassword of domain registered) 

Send request to callback url i.e ZK Server which sends

EncryptedSecret: <string> (public key encoded **DID** (which is randomly generated)),
domainPublicKey: <string>
encryptedPassword: <string>
usersPublicKey <string> (this is mobile app guy)

Output:

Successful, 200 (from ZK Server) which will check domainPublicKey and encryptedPassword match record and save the message with mobile app's user's public key. 

On Device, DID is saved as user's identity which is never transmitted over the network i.e never leaves the phone's memory.

4. API for Integrating Sign In Button on 3rd party app

On ZK Phone,

API Example Input:

qr: <image> (EncryptedSecret, encoded) 

ZK App will generate proof given: Public Inputs:

1. F (encryption function) (known)
2. Hash (algortithm, most probably sha3 for eth) (known)
3. EncryptedMessage, from QR code (received)

Private Input:

1. Private Key (Secret Key)
2. Salt

   So the zksnark should have a system of constraints that implement the following:
   𝐻−Hash(𝑆)==0
   encryptedSecret−f(𝑆,salt)==0

   OffChain ZK App will do this:

   const { proof, publicSignals } = await snarkjs.groth16.fullProve(
   privateVariables, //privateVariables
   "circuits/quadratic.wasm",
   "circuits/quadratic.zkey"
   );
   // Construct the raw calldata to be sent to the verifier contract
   const rawcalldata = await snarkjs.groth16.exportSolidityCallData(
   proof,
   publicSignals
   );
   jsonCalldata = JSON.parse("[" + rawcalldata + "]");
   console.log("JSON Calldata: ", jsonCalldata);

Then ZK App will send the proof to the smart contract:

await verifier.verifyProof(
  jsonCalldata[0],
  jsonCalldata[1],
  jsonCalldata[2],
  jsonCalldata[3]
)

ZK Server will listen to the event from this transaction and check if user is authenticated and return the response to 3rd party app.

Output:

tx: <tx hash>