© 2020 Blockchain Commons
Authors: Wolf McNally, Christopher Allen
Date: June 6, 2020
Revised: November 25, 2023
Bitcoin, Ethereum, and other cryptocurrencies use addresses as destinations for funds. Addresses are generated from public keys, which were in turn generated from private keys. Ultimately an address is just a string of bytes, but to facilitate recognition and handling by humans they are encoded as base58 (Bitcoin), bech32 (Bitcoin) or base16 (Ethereum). Encodings such as Bitcoin's include one or more tag characters at the front to help identify the string as an address, e.g., 1 for a Bitcoin P2PKH address or m for a Bitcoin testnet address, or bc1 for a Bitcoin Bech32-encoded address.
This document defines the following UR types along with their corresponding CBOR tags:
| UR type | CBOR Tag |
|---|---|
| ur:address | #6.40307 |
These tags have been registered in the IANA Registry of CBOR Tags.
This specification defines a UR type address (CBOR tag #6.40307) for encoding and transmitting cryptocurrency addresses.
The info field of the CBOR type defined herein references the coininfo type defined in BCR-2020-007. This structure encodes both the type of coin and the network (main or test) the address is to be used with. If the optional info field is omitted, its defaults (mainnet Bitcoin address) are assumed.
The data field encodes the raw byte string comprising the address.
Note: This specification describes version 2 address (#6.40307), which differs from version 1 crypto-address (#6.307) only in the UR type and CBOR tag it uses. Version 1 crypto-address is deprecated, but may still be supported for backwards compatibility.
The following specification is written in Concise Data Definition Language CDDL.
When used embedded in another CBOR structure, this structure should be tagged #6.40307.
tagged-address = #6.40307(address)
address = {
? info: tagged-coininfo,
? type: address-type,
data: bytes
}
info = 1
type = 2
data = 3
address-type = p2pkh / p2sh / p2wpkh
p2pkh = 0
p2sh = 1
p2wpkh = 2
; The `type` field MAY be included for Bitcoin (and similar cryptocurrency) addresses, and MUST be omitted for non-applicable types.
; `data` contains:
; For addresses of type `p2pkh`, the hash160 of the public key (20 bytes).
; For addresses of type `p2sh`, the hash160 of the script bytes (20 bytes).
; For addresses of type `p2wphk`, the sha256 of the script bytes (32 bytes).
; For ethereum addresses, the last 20 bytes of the keccak256 hash of the public key (20 bytes).
- A mainnet Bitcoin address.
1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2
- Decoded
$ bx address-decode 1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2
wrapper
{
checksum 1802900980
payload 77bff20c60e522dfaa3350c39b030a5d004e839a
version 0
}
- In the CBOR diagnostic notation:
{
3: h'77bff20c60e522dfaa3350c39b030a5d004e839a' ; data
}
- Encoded as binary using [CBOR-PLAYGROUND]:
a1 # map(1)
03 # unsigned(3) ; data
54 # bytes(20)
77bff20c60e522dfaa3350c39b030a5d004e839a
- As a hex string:
a1035477bff20c60e522dfaa3350c39b030a5d004e839a
- As a UR:
ur:address/oyaxghktrswzbnhnvwcpurpkeogdsrndaxbkhlaegllsnyolrsemgu
- UR as QR Code:
- A testnet Ethereum address.
0x81b7E08F65Bdf5648606c89998A9CC8164397647
- In the CBOR diagnostic notation:
{
1: 40305({ / info: coininfo [BCR-2020-007] /
1: 60, / type: coin-type-eth (0x3c) [BCR-2020-007] /
2: 1 / network: testnet-eth-ropsten [BCR-2020-007] /
}),
3: h'81b7e08f65bdf5648606c89998a9cc8164397647' / data /
}
- Encoded as binary using [CBOR-PLAYGROUND]:
a2 # map(2)
01 # unsigned(1) info
d9 9d71 # tag(40305) coininfo
a2 # map(2)
01 # unsigned(1) type
18 3c # unsigned(60) coin-type-eth
02 # unsigned(2) network
01 # unsigned(1) testnet-eth-ropsten
03 # unsigned(3) data
54 # bytes(20)
81b7e08f65bdf5648606c89998a9cc8164397647
- As a hex string:
a201d99d71a201183c0201035481b7e08f65bdf5648606c89998a9cc8164397647
- As a UR:
ur:address/oeadtantjsoeadcsfnaoadaxghlyrlvtmyihryykielnamspnlmkptsflyieeskoflkovdfdlb
- UR as QR Code:
