zeke-circuits

DKIM Verification:

The circuits includes an EmailVerifierPaypal component that verifies the DKIM (DomainKeys Identified Mail) signature of the email.
It takes the email header data, public key (modulus), signature, and body data as inputs.
The DKIM verification ensures that the email is authentic and hasn't been tampered with.
The circuit outputs the header hash, email hash (using Poseidon hash), and post-compute hash.

Regular Expression (Regex) Extractions:

The circuit uses several regex components to extract specific information from the email header and body.
It extracts the "From" email address, PayPal send amount, and timestamp using regex patterns.
The extracted data is then processed and converted into signals for further use.

Email Extraction:

The circuit extracts the offramper and onramper email IDs from the email body and header, respectively.
It uses regex components (PaypalOfframperEmailExtraction and PaypalActorEmailExtraction) to match and extract the relevant email IDs.

Merkle Tree Hashing:

The extracted offramper and onramper email IDs are hashed using a Merkle tree.
The email IDs are first packed into fixed-size chunks (email_pack_size) and then hashed using the Poseidon hash function to create leaf nodes.
The Merkle tree is constructed using the MerkleTreeChecker component, which takes the leaf nodes, path elements, and path indices as inputs.
The circuit outputs the Merkle root hash for both the offramper and onramper email IDs.

Nullifier Generation:

The circuit generates a unique nullifier for the email using the EmailNullifier component. It takes the header hash and a random value (derived from the signature) as inputs and outputs the nullifier. The nullifier serves as a unique identifier for the email and prevents double-spending or replay attacks.

Intent Hash:

The circuit includes an intent hash input, which is used to tie the proof to a specific transaction intent.