SmsTx

Users interact with the wallet by sending plain texts to a common service number (SEC). On first contact, the platform runs a t-of-n DKG ceremony to generate a shared key for the sender’s phone number; the key is split across independent nodes. Subsequent messages like “send $10 to Himang” trigger a malicious-secure MPC-ECDSA signing flow: nodes verify the command is authorized by the sender’s number, jointly produce a valid (r,s,v) over secp256k1, and broadcast the transaction. If the recipient (e.g., Himang) isn’t onboarded yet, the system auto-onboards them by running DKG for their number before transferring, so value can be pushed to anyone reachable by SMS. The private key never exists in one place, eliminating a single point of compromise, while UX stays as simple as texting

Identity & Auth

Primary identifier: phone number bound to a DKG-generated key. Authorization: messages from that number are the only ones allowed to initiate signatures for that key.

Crypto Core DKG (Feldman VSS) to derive per-user key shares and a group public key. MPC-ECDSA (GG18/GG20/CGGMP-class) to sign without secret reconstruction. Ethereum compatibility: keccak256, low-S (EIP-2), correct v via recovery. Messaging Layer Ingests SMS from the SEC number, parses intents (send, check balance, etc.). Stateless commands; idempotency tokens and replay protection baked in.

Orchestration Coordinator dispatches to DKG/TSS nodes; nodes exchange commitments, ZK proofs, partials. Aggregator computes final (r, s); derives v matching the user’s group pubkey. Security No secret reconstruction, secure nonce generation, ZK correctness proofs. Rate-limits, per-number spend caps, allowlists/denylists, and optional PIN/OTP step-up. Audit logs with message digests