Who stands to benefit from a spam attack on the Bitcoin network?

As discussed earlier, the Bitcoin network has recently been flooded with a lot of spam transactions. While at least some of this was an honest stress test, it brought more attention to the fact that the Bitcoin network can be pushed to its limits with relatively low cost by anyone. While the network should be resilient against zero fee transaction spam attack, putting some money and effort into the attack can make it seem like a lot of honest transactions with relative ease.

Now, since we know how the Bitcoin network could be destabilized, let us ponder who might benefit from such actions.

DISCLAIMER: while I will be mentioning a lot of specific examples of peoples and projects that might benefit from such an attack, please treat them only as illustrative examples. I have no evidence of their involvement in the attacks, nor do I believe any of them would employ such a strategy.

The usuals

Since we're talking about an attack on Bitcoin, lets get the usuals out of the way - governments, big banks, PayPal, etc. wanting to bring Bitcoin down since it challenges "the old ways". There isn't much new to add to these speculations or motivations, so might as well skip this part of the debate for expediency's sake.

The direct competitors

Bitcoin has been copied so many times people lose count. There is never a shortage of copycoins out there. Since Bitcoin has a throughput issue of handling a lot of transactions, you can easily see someone creating an altcoin with higher block sizes and faster blocks to sell itself as the solution to Bitcoin. More ambitiously, you can look at coins that have added some improvements to the protocol to combat spam, like Litecoin for example. Sustain a spam attack on the Bitcoin network long enough to sell your story of being the savior of cryptocurrencies and you might just be able to push up the price of your coin high enough to turn a profit.

The speculators

Just like you can speculate on the price of altcoin alternatives going up, you can also try speculating on the price of Bitcoin being affected by the spam. Alternatively, you could try to cause something similar to "trade engine lag" on the Bitcoin network and try to game some exchanges while other traders would have trouble moving their coins onto the exchange to cash in.

The solution evangelists

Even if we don't look at the altcoin space, we can see a lot of people with an agenda of where the Bitcoin code should move towards. Whether they are doing it for profit or for personal satisfaction, there is a potential for those evangelist of their own solutions to attack the network and push their code onto others.

Below are some examples (again, only illustrative examples, read the disclaimer) of potential solution evangelists.

Sidechains is an interesting concept of how to move a lot of transactions off the Bitcoin blockchain while still having a currency tightly tied into the Bitcoin itself. As (to the best of my knowledge) sidechains are still impossible to fully implement into the Bitcoin network without a soft fork, using the spam attack as an opportunity to push for a fork would be beneficial to them and enable sidechains to come to the Bitcoin network.

The debate over Bitcoin block size increase has been a hot topic for a few months now. The topic has been pushed most notably by Gavin Andresen, with some people even speculating on "gavincoin" becoming a reality (read more here). More so than Sidechains, the concept is not possible without a hard fork to the Bitcoin protocol, thus pushing the block size increase amid the spam attack would make the core developers more urged to consider going through with the fork to solve the issue.

Finally, something that doesn't require a hard fork - transaction filtering. This approach relies on being able to identify which Bitcoin transactions are spam and which are legitimate use cases and prevent the spam from propagating through the network. If enough nodes in the network would stop spam transactions, the network as a whole could develop herd immunity against spam. However, the same mechanism could be used to deny some Bitcoin businesses' transactions from reaching the miners. Such transaction censorship has been tried to pass unnoticed in the past by Luke-Jr, and could possibly be tried again along with more honest spam filtering.

The off-chain alternatives

Since moving transaction on the chain can be a problem, some people might propose solutions based on transactions being processed off-chain instead. Examples of such alternatives would include the Lightning Network, Ripple, Open Transactions or shared wallet providers such as Coinbase. If the off-chain solution can deliver bitcoins to people faster than the real network and some people don't know or don't care how they receive the coins, they might appear as a legitimate replacement for sending real Bitcoin transactions to some people. This might be also the case when Bitcoin transactions are too pricey to be included in the blockchain.

Crypto 2.0s eliminating competition

There are a lot of Crypto 2.0s out there. A good deal of them rely on the Bitcoin network to function - Colored Coins, Omni or Counterparty for example. There are also some emergent platforms that offer services tied to the Bitcoin blockchain, such as Factom. If the transactions for those networks can't make it into the Bitcoin blockchain, the network itself performs worse and suffers as a result. Their alternatives on the other hand stand to benefit from people potentially switching over. Ripple could benefit if Omni is not performing well, Ethereum stands to benefit from Counterparty being slow, etc. While being on the Bitcoin blockchain has been a selling point for a lot of companies, it can turn into a detriment if the Bitcoin network is overloaded.

Extra: bribing the miners for their compliance

As a side-note, it might be interesting to consider how some parties might want to even further push their agenda onto the network by essentially bribing the miners for their compliance.

Say, if someone wanted to eliminate some "spammy" transactions from the Bitcoin network, whether it's SatoshiDice's dust transactions or perhaps Omni transactions. They could easily set up an anonymous website claiming they will pay every miner X amount of bits for every block they create that complies with their spam filter. As long as they offer more than the miners stand to earn from the transaction fees, there is a benefit to them complying. With the excuse of excess spam, the miners can't be entirely held accountable for some transactions not making it into the block. Since the miners can be paid directly to their coinbase address, everything is transparent and nobody needs to agree to collude.

Conclusions

A stress test of the Bitcoin network can be all about preparing for the higher transaction volumes that are to come in the future, but it can also be a way for some people and organizations to further their agenda. While it might be still really early for such high-level politics to surface around Bitcoin, who knows what the future might hold?