[Ads-l] double-spend (2009), to double-spend (2010) (crypto)

[Barretts Mail]

A problem in electronic currencies that developers have to overcome is user tricking the system and using (sending) a quantity of currency twice. This is known as “double-spending.” Wikipedia discusses this (https://en.wikipedia.org/wiki/Double-spending <https://en.wikipedia.org/wiki/Double-spending>), with citations back to 2007.

1. 3 January 2009 (Google-dated)
Advanced Network Security: -. Bitcoin
Jaap-Henk Hoepman
http://www.cs.ru.nl/~jhh/ans/slides/8-blockchain.pdf <http://www.cs.ru.nl/~jhh/ans/slides/8-blockchain.pdf> 

How to prevent a double spend?

2. 5 October 2012 (date from Google)
What is a double spend?
https://bitcoin.stackexchange.com/questions/4974/what-is-a-double-spend <https://bitcoin.stackexchange.com/questions/4974/what-is-a-double-spend>

As someone who uses Bitcoin, what do I need to know about how the Bitcoin system prevents double spends? Are there still circumstances where they can occur?

3. 14 January 2016
The De-Throning of Bitcoin: If It Happens, This Will Be Why
The Daily Decrypt 
3:17 at https://www.youtube.com/watch?v=M6Sf7kcbDWk <https://www.youtube.com/watch?v=M6Sf7kcbDWk>

Core bitcoin developer Peter Todd recently carried out a successful double-spend, meaning he sent coins to one address and then sent those very same coins to another.

=====
To double-spend

29 December 2010
Interview: How Bitcoin Created a Decentralized Crypto-Currency
Klint Finley
https://readwrite.com/2010/12/29/interview-bitcoin/ <https://readwrite.com/2010/12/29/interview-bitcoin/> 

If a double-spend is broadcast, then some of the nodes will see one of the spend transactions first, and others will see it second.

…

Good question! I wish somebody would write a tool to listen on the network for attempted double-spends.

Can double-spends happen accidentally?

It is really hard to double-spend accidentally.

=====

Benjamin Barrett
Formerly of Seattle, WA
------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org