- Add ephemeral_public_key and requires_payment_message fields to EncryptedPaymentRequest + updated descriptions
- Update EncryptedPayment and EncryptedPaymentACK message descriptions to use ECDH-derived key for signature instead of each side's public key
- Slim down message content-types
- Add EncryptedPayment and EncryptedPaymentACK creation detail steps
- Add updated paymentrequest.proto to bip-ir/ directory
- Add additional flow diagrams for various mobile-to-mobile / Store & Forward scenarios
- Update InvoiceRequest notification_url definition to use SHOULD instead of MAY
- Capitalize MUST, SHOULD, etc.
- Update InvoiceRequest Message Creation steps to specifically define behavior for empty amount or amount out of bounds
- Add implementation section with references to Addressimo reference Store & Forward server and a client implementation in functest_ir.py
- Add flow diagrams for BIP70 extension and moble-to-mobile example with store and forward service
- Make Abstract more readable
- Update Sender definition and acronym descriptions
- Added comments to ReturnPaymentRequest definition
- Bold ECDH and AES Setup notes and added "(see below)" for reference
