Circle Research has introduced Recibo, an open-source smart contract prototype designed to integrate encrypted messaging into ERC-20 token transactions, addressing the lack of memo lines in blockchain payments. This tool allows payers to add encrypted messages to transaction calldata, supporting arbitrary message formats and encryption algorithms, and it is compatible with standard ERC-20 tokens as well as gasless transactions through ERC-2612 and ERC-3009. Recibo enables merchants and financial institutions to attach digital receipts, credentials, and standard payment messages, akin to the SWIFT network, directly into blockchain transactions, thereby enhancing functionalities for accounting reconciliation and regulatory compliance. The prototype, although not audited and intended for educational purposes, demonstrates cryptographic agility and allows for secure communication by encoding encrypted messages as bytes, while also offering the option to store sensitive data offchain to mitigate risks and reduce gas costs.