Antminer X9
Monero ASIC Miner
1000KH
HASHRATE
2.47W/KH
EFFICIENCY
2470W
POWER
£856.76
EST. MONTHLY
206
DAYS
EST. ROI
BIP 75 Encrypted Payment Exchange: This guide explains BIP 75 Out of Band Address Exchange using Payment Protocol Encryption in plain English. It covers the problem behind the BIP, why it matters and whether the proposal is part of Bitcoin today.
TL;DR
- What it is: BIP 75 extended the BIP 70 Payment Protocol with optional sender authentication and encrypted out-of-band exchange of payment details. It supported direct and store-and-forward workflows using ECDH-derived encryption.
- Why it matters: BIP 75 explored private, authenticated address exchange, but its safety depends on complex legacy payment-protocol and PKI handling. Current systems should use maintained payment methods and keep any archival support tightly isolated.
- Current position: BIP 75 extended the BIP 70 Payment Protocol with optional sender authentication and encrypted out-of-band exchange of payment details.
BIP 75 Encrypted Payment Exchange in simple English
BIP 75 Encrypted Payment Exchange: The sender could sign the initial request and provide certificate material, allowing the receiver to evaluate who requested payment information.
Simple example
A node operator is checking BIP 75 Encrypted Payment Exchange. This made address release permissioned and reduced exposure of payment details to intermediaries beyond ordinary TLS termination.
Key terms in plain English
- BIP:
- Bitcoin Improvement Proposal: a document describing a proposed rule, standard or process. Its status must be checked separately.
- Bitcoin Core:
- Widely used software that validates Bitcoin and can provide wallet, network and operator tools.
- Node:
- A computer running Bitcoin software that checks data and communicates with other peers.
What BIP 75 added
The sender could sign the initial request and provide certificate material, allowing the receiver to evaluate who requested payment information. The returned PaymentRequest was encrypted before transport. This made address release permissioned and reduced exposure of payment details to intermediaries beyond ordinary TLS termination.
Identity mechanisms
The proposal extended pki_type beyond BIP 70 X.509 to OpenPGP and secp256k1 ECDSA variants using SHA-256. A signature proves control of the selected credential, not the truth of a displayed real-world identity. Trust anchors, revocation, name binding and user-interface wording remained application responsibilities.
ECDH and encrypted return
Parties derived a shared secret through elliptic-curve Diffie-Hellman and used it to protect the payment request. Correct nonce use, authenticated encryption, key validation and transcript binding are essential. A bespoke implementation can leak keys or accept modified ciphertext even when the high-level ECDH idea is sound.
Store-and-forward model
An asynchronous service could retain encrypted messages for a mobile or offline wallet. Encryption could hide contents and prevent undetected modification, but the service still observed timing, endpoints and message sizes and could delete or delay traffic. Availability and metadata privacy were separate from confidentiality.
Address books and privacy
A wallet could retain a payee public key and request a fresh address for each payment instead of reusing a static address or exposing an xpub. That improves some privacy properties but creates a live-service dependency. Failure must stop safely rather than fall back to an old or unauthenticated address.
Legacy deployment boundary
BIP 75 depended on BIP 70 structures and certificate ecosystems that have seen reduced support. Bitcoin Core removed its BIP 70 payment-protocol support from the GUI release line. Historical Deployed status does not prove current wallet interoperability, maintained cryptography or appropriate certificate validation.
How specialists test it
Developers test the proposal with made-up data on an isolated test network. They check normal cases and deliberately invalid cases. Different implementations should reach the same result before anyone relies on the proposal.
Frequently asked questions
What is the main point of BIP 75 Encrypted Payment Exchange?
BIP 75 Encrypted Payment Exchange: The sender could sign the initial request and provide certificate material, allowing the receiver to evaluate who requested payment information.
For BIP 75 Encrypted Payment Exchange, what should a beginner know about what BIP 75 added?
The sender could sign the initial request and provide certificate material, allowing the receiver to evaluate who requested payment information.
For BIP 75 Encrypted Payment Exchange, what should a beginner know about identity mechanisms?
The proposal extended pki_type beyond BIP 70 X.509 to OpenPGP and secp256k1 ECDSA variants using SHA-256.
For BIP 75 Encrypted Payment Exchange, what should a beginner know about ecdh and encrypted return?
Parties derived a shared secret through elliptic-curve Diffie-Hellman and used it to protect the payment request.
Conclusion
BIP 75 explored private, authenticated address exchange, but its safety depends on complex legacy payment-protocol and PKI handling. Current systems should use maintained payment methods and keep any archival support tightly isolated.
Primary sources
Check the current specification status and the documentation for the exact implementation you operate before moving production funds or changing a mining node.
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