BUIP092: Workshop on Instant Transactions for Bitcoin
Proposer: Peter Rizun
Submitted on: 2018-08-06
Status: passed


To request Bitcoin Unlimited (BU) membership approval to allocate BU
funds to sponsor a multi-day developer workshop dedicated to improving
instant transactions for Bitcoin Cash.

Location & Date

Location: Gargnano (Lake Garda), Italy Date: 16 - 19 October, 2018

Workshop Description

A collaborative and highly-technical three-day workshop with the goal of
improving instant transactions for Bitcoin Cash. Attendance will be
limited to active developers, researchers, and key stakeholders. (15 to
30 participants.)

The workshop’s main focus is to develop strategies for improving instant
transactions that can be implemented over the short term (addressing the

problem). Examples include double-spend relay, super-standard
transactions, and double-spend proofs. A secondary focus will be on
longer-term ideas to address the RBF double-spend problem, such as those
based on pre-consensus techniques.

The workshop will include round-table discussions, working groups, and
technical presentations.

Tentative Schedule:

  • Day 1: Defining the problem
    • How can double-spends of instant transactions be carried out
    • Statistics on 0-conf double-spends
  • Day 2: Exploring solutions
    • Double-spend relay vs. double-spend proofs
    • Super-stand transactions
    • Pre-consensus
  • Day 3: Forging a path forward
    • Coordinating between node implementation (ABC, BU, XT, Flowee
      the Hub), SPV wallets, businesses, and miners
    • Best practices when accepting instant transactions and
      understanding risk level


This workshop hopes to encourage new developers to get involved and
there will be an open call for proposals to present. Depending on
demand, a small number of public tickets may be available.


The workshop organizers seek up to $50k of BU funds to sponsor the

These funds will be used to pay for the meeting rooms, A/V requirements,
and catering. The funds will also be used, on a case-by-case basis, to
pay travel and accomodation costs for workshop participants who do not
have external sources of funding (e.g., developers).

NOTE: Workshop organizers are seeking additional sponsors, with the goal
of reducing BU’s direct costs to $30k. Please contact us if you would
like to be a sponsor for this event.

Workshop Output

Presentations made during the event will be recorded and published on
Youtube. These videos will be useful for educating the broader community
about instant transactions, their risk level, and how those risks may be

Live streaming of the presentations is a possibility.


  1. Eliminating the (fixable) vulnerabilities of instant transactions is
    low-hanging fruit that will greatly improve BCH’s function as
    digital cash.
  2. Educating the public on best-practices when accepting instant
    transactions, and understanding their risk levels, will encourage
    greater use of instant BCH transactions for payments.
  3. Sponsoring the workshop will further establish Bitcoin Unlimited as
    a center of excellence for Bitcoin research and full-node software