Glossary

Term	Definition
ASP	Association Set Provider — maintains lists of approved/excluded participants for compliance
Batch Operator	Component that accumulates x402 payment requests and executes them in temporal batches
Blinding	Random factor added to a commitment to prevent brute-force amount recovery
BN254	Elliptic curve used for Groth16 proofs (same as Ethereum’s alt-bn128)
Commitment	`Poseidon2(amount, pubKey, blinding, 0x01)` — hides a deposit in the Merkle tree
Domain Separator	Constant appended to Poseidon2 inputs to prevent cross-domain hash collisions
ext_amount	Signed amount: positive for deposits, negative for withdrawals, zero for transfers
extDataHash	Hash of external data (recipient, amount, encrypted outputs) — prevents front-running
Freighter	Stellar browser wallet extension used for signing transactions
Groth16	Zero-knowledge proving system with constant-size proofs and verification
MCP	Model Context Protocol — standard for connecting AI agents to external tools
Merkle Tree	Binary tree of commitment hashes. Proves a commitment exists without revealing which one.
Note	Private data for a commitment: amount, blinding, leaf index. Needed to spend the commitment.
Nullifier	`Poseidon2(commitment, pathIndices, privKey, 0x02)` — published when a note is spent. Prevents double-spend.
Pool	The Soroban smart contract that holds USDC and manages the commitment Merkle tree
Poseidon2	ZK-friendly hash function optimized for arithmetic circuits. Native on Stellar Protocol 25.
Privacy Pool	Architecture where multiple users share a single pool to break the link between deposits and withdrawals
Protocol 25	Stellar’s “X-Ray” upgrade (Jan 2026) that added BN254 and Poseidon2 host functions
Proxy	The Lateo privacy proxy server that generates ZK proofs and manages agent state
SEP-53	Stellar Ecosystem Proposal for message signing — used for Freighter authentication
Soroban	Stellar’s smart contract platform (Rust-based)
Stroops	Smallest unit of Stellar assets. 1 USDC = 10,000,000 stroops.
transact()	The pool contract’s main function — atomically verifies proof + transfers funds + updates tree
Trusted Setup	One-time ceremony to generate Groth16 proving and verification keys
UTXO	Unspent Transaction Output — the note model Lateo uses (similar to Bitcoin, Zcash)
x402	HTTP 402-based pay-per-request protocol backed by Coinbase
Zero-Knowledge Proof	Cryptographic proof that a statement is true without revealing any information beyond the statement itself