[bitcoin-dev] QR code alternatives (was: Proposal: extend bip70 with OpenAlias)

Thomas Voegtlin thomasv at electrum.org
Tue Jul 21 14:58:39 UTC 2015

Le 20/07/2015 16:40, Mike Hearn a écrit :
> If we accept a single payment address i.e. no clever tricks around merge
> avoidance, such a QR code could look like this:
> bitcoin:1aBcD1234....?x=serialized_payment_request
> However this requires text mode and wastes bytes at the front for the URI
> type.

It is possible to be both backward-compatible and to avoid wasting space
in URIs, if we simply assume that the payment request is a single
standard output + amount (that scenario will probably cover 99% of the
cases, and the few other cases may not need QR codes). We generate a
serialized bip70 PR from the parameters found in the URI, sign that
string, and add the signature to the URI.



'time' is the timestamp of the request
'exp' is the duration of validity, 1 week here
(it saves a few bits to express it that way)

'name' is the domain name of the signer
'sig' is the signature

The QR code derived from that URI is perfectly scannable with a phone.

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