Talk:Double-spending

Wish: list of approaches to double-spending problem, compared and contrasted

Without doing original research, ha. if I recall correctly double-spending:

• has been demonstrated as a working fraud vector against at least one subway pass card system in use in multiple major cities (as if any minor systems have subways)
• is mitigated in the Bitcoin system by distributing the central recording authority function
• is mitigated in the MintChip system by embedding a private key and circuitry for using it in EEPROM/FPGA devices which are too small to read and copy without destroying them

75.87.130.113 (talk) 03:09, 24 April 2012 (UTC)

Ignore ripscams, but include bitcoins. please review and insert in appropriate section

roughly translated, please put into proper english and expend article with this.

Wherever double spending offers a monetary incentive, technically skilled individuals may spare no effort in exploiting potential attack vectors.

Such vectors are often specialised Race Condition.

In the Bitcoin protocol double spend is possible if the attacker succeeds in getting two contradicting transactions confirmed at the same time. Commonly, the attack is mitigated by requiring a transaction to be consistent with a certain amount of consecutive confirmations before considering it valid. An attacker would very unlikely have the relative computing power share at his hands required to confirm his fraudulent spendings before others in the distributed network invalidate either of the transactions, eliminating the illegal second spending. — Preceding unsigned comment added by Lmx613 (talk • contribs) 11:37, 9 January 2014 (UTC)

Article's lead has become indecipherable

I came here to understand Double Spending, but the page is literally indecipherable. For example: "...such double-spending are Inflation by "create" a new amount of not-removed currency...". This makes no sense in English. I appreciate someone taking the time to expand the ideas here, however, the page is unreadable. If someone that is fluent in written English and also highly knowledgeable of cryptocurrency concepts could please edit the page so that it can actually be used that would be great. This is not a criticism. I'm merely trying to bring awareness to this issue in hopes that it can be resolved. Jonassteinberg (talk) 18:08, 16 July 2017 (UTC)jonassteinbergJonassteinberg (talk) 18:08, 16 July 2017 (UTC)

Merger proposal

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was redirect. Uncontested, not much content that ought to be merged right now IMO. Џ 13:30, 30 January 2019 (UTC)

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I propose to merge 2018 double-spend attacks on Equihash-based cryptocurrencies into Double-spending. For WP:MERGEREASON three "If a page is very short and is unlikely to be expanded within a reasonable amount of time, it often makes sense to merge it with a page on a broader topic" and because I don't think the event is independently notable. The Double-spending article can cover non-notable attacks on notable cryptocurrencies, of which Bitcoin Gold is already mentioned. @Xinbenlv, Ceosad, Jtbobwaysf, and Retimuko: Pinging participants of the discussion at Talk:Bitcoin_Gold#Propose_unmerge_with_Bitcoin_Gold_Double_Spend_Attack. Џ 21:12, 25 December 2018 (UTC)

• Neutral ok with me, thanks for asking. Xinbenlv (talk) 03:05, 7 January 2019 (UTC)
• Support this proposal to merge as I think the 2018 double spend attacks article is unlikely to get any more content (as it is a single event page) and merging it will allow the broader double spend attack article to grow its content. Seems like an interesting subject and if there were a few different double spend attacks covered on one general article it might be more encyclopedic. Jtbobwaysf (talk) 06:47, 26 December 2018 (UTC)
• Support The page as it stands is not worthy of an article. There is currently some information on Bitcoin Gold that may be worth merging over, otherwise I would even suggest nominating this article for deletion. Dr-Bracket (talk) 04:08, 16 January 2019 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Empirical examples of double spending (or lack thereof)

It would be nice to add a few case studies if there're things like that. Otherwise, should say somewhere that no known double spending ever worked in proof of work contexts (that isn't a 51% attack) PolyCreator (talk) 06:12, 20 April 2022 (UTC)

There's at least 1 known double-spend on Bitcoin back in 2013. Here's the post-mortem of the 0.8.0 hard fork and double-spend attack. Though I'm not sure why you added the "(that isn't a 51% attack)" part. Any blockchain that allows for a double-spend without a majority attack isn't functional. HSukePup (talk) 09:20, 2 December 2025 (UTC)

There was a theoretical vulnerability in Bitcoin Core 0.14.x and Bitcoin Knots 0.14.x to 0.15.x through 0.16.3 that would allow for double-spending in a prior block without needing to 51% attack or reorg a network. This was never exploited. [[https://nvd.nist.gov/vuln/detail/cve-2018-17144 CVE-2018-17144], [https://bitcoincore.org/en/2018/09/20/notice/ Disclosure of CVE-2018-17144]] — Preceding unsigned comment added by HSukePup (talk • contribs) 07:43, 13 December 2025 (UTC)

Double Spend problem, is not a digital problem - its a design problem

"Double-spending is a fundamental flaw in a digital cash protocol" NOOOOO

For something to be Money, it is required to be scarce. This is true of any money, including PAPER CURRENCY

Technology is used in the DESIGN of any currency to prevent Double Spend AKA Counterfeit!

When an issuer of paper currency employs special paper or printing methods and penalties for fraud they are attempting to enforce scarcity, prevent double spending.

Example; 17th century - new france, card money were printed on cards printed in france and signed by intendant, governor, and treasurer.

Double Spend problem, is not a digital problem of electronic cash - its a fundamental design problem of money generally.

76.65.23.149 (talk) 18:09, 18 April 2024 (UTC)

Too many off-topic sections

Too much of this article is spent discussing other topics. It's currently divided up about:

• 20% - double-spend
• 20% - explaining decentralized consensus protocols: only half of this is about double-spends
• 30% - 51% attacks: not related to double-spends
• 30% - Atomic Ownership Blockchains: very little ties back to double-spends

I recommend greatly reducing the size of the "51% attacks" and "atomic ownership blockchains". They are too off-topic. HSukePup (talk) 00:42, 3 December 2025 (UTC)

I've re-written the "51% attack" section and its examples so that it fully relates back to the topic of "Double-spending) and is no longer off-topic. HSukePup (talk) 01:38, 3 December 2025 (UTC)

I've re-written more of the article to be clearer, especially the unsourced parts. I've also added sources and made the sections more concise.

I am concerned about the "Atomic Ownership Blockchains" section. It relies on a single primary source that isn't referenced anywhere else on the Internet. Some of it didn't even match the primary source. The whole section was overweight, so I've reduced its size to the parts relevant to Double-spending. I can also tell that AOB is just a minor variation of Federated Byzantine Agreement that's used for Stellar Consensus protocol and Ripple Ledger consensus. All it does is replace UTXOs with individual private blockchains. HSukePup (talk) 07:44, 13 December 2025 (UTC)