Octojoin - better Bitcoin privacy

[dkbit98]

Few days ago I found out about interesting way for improving privacy on Bitcoin and it's called Octojoin.
This is the new privacy technique that obfuscates transaction inputs and hides payment amounts by combining on-chain transactions with off-chain coin swaps.

Key features of Octojoin:

- Inputs obfuscation (mixing users UTXO with other parties)
- Hidden payment amounts
- Silent payment address for outputs

Octojoin problem is that no mainstream bitcoin wallet supports it so far, and this is still proof of concept.
It can work with other privacy methods for bitcoin, and it is not designed to replace them.

More information about Octojoin can be found here:
https://octojoin.github.io/
https://uncensoredtech.substack.com/p/octojoin

Did anyone here tested Octojoin?

[BitMaxz]

Did anyone here tested Octojoin?

I've never heard of this before; it looks similar to CoinJoin, but the only difference is it combines on-chain and off-chain transactions via coin swaps.
I saw a post on a Google Group mentioning this project 2 years ago. It's not popular yet, so there's not so much data about this. Most of what I found is the OctoJoin from UK related to electricity.


This is interesting, but I couldn't find any wallets yet that have this feature to test it out.

[nc50lc]

Octojoin problem is that no mainstream bitcoin wallet supports it so far, and this is still proof of concept.

That will take a while, the pre-requisites are steep for most wallets.
A side chain or at least swap capability and the ability to create silent payment address (and its back end)
But this can be a third-party feature or a plugin at least, excluding silent payments if the wallet already supports it.

I don't know about the name though,
"Octo" sounds more like "Eight" than the animal that they want to portray with the concept.
So at first glance, I though that this is limited to 8 participants.

[ABCbits]

Users should label some UTXOs as “octojoin” so that they can be used in octojoin transactions. Ideally, these UTXOs should be ones that have been swapped with others and are linked to someone else’s transaction history.

Input Obfuscation with Off-Chain Swaps

Do off-chain swaps (e.g. statechain, submarine swaps, or coinswap) to obtain UTXOs with different histories. Ensure that all inputs come from other users except one belonging to the sender, making it difficult for on-chain analysts to determine ownership.

It's interesting approach to confuse blockchain analysis that the UTXO multiple belong to different people. The trade-off between multiple participant (in PayJoin) and having multiple UTXO from different source (Octojoin) is acceptable, if user properly label and group their address/UTXO.

This is interesting, but I couldn't find any wallets yet that have this feature to test it out.

Based on link shared by OP, it's not exist. If you really want to give it a try, check https://github.com/octojoin/poc. But i only find very minimal explanation about using it.


P.S. This thread is more suitable on "Development & Technical Discussion" board.

[satscraper]

I have read the article about Octojoin and ^{after careful pondering of the underlying tech} came to conclusion that it is not necessary for wallet developers to make heavy weather of it and replace  SP with Octojoin. Octojoin, in fact, delivers very limited privacy benefits compared with SP and at the same time makes wallets more vulnerable to attacks due to their more complex codebase with new trust dependencies, swap protocols, input-type mixing, labeling, to name only a few.

So, it would be enough for wallets to use SP as the de facto standard in the field. ^{Sure, extraordinary wallets might want to consider Octojoin as an option, but I don't think it could be popular among users.}

[dkbit98]

That will take a while, the pre-requisites are steep for most wallets.
A side chain or at least swap capability and the ability to create silent payment address (and its back end)
But this can be a third-party feature or a plugin at least, excluding silent payments if the wallet already supports it.

Only wallet using plugins is Electrum wallet, and they don't support silent payments yes.
Best candidate is probably Cake wallet for supporting Octojoin.

"Octo" sounds more like "Eight" than the animal that they want to portray with the concept.
So at first glance, I though that this is limited to 8 participants.

I don't know what was the inspiration for Octojoin name, but you are correct that Octo means 8 in latin labnguage,
but we are also using word October for 10th month in calendar year, not 8th month, same as Septem means 7, and we use it as 9th month in calendar year

[PrivacyG]

It would be interesting to see a detailed Privacy level comparison between Coin Joins and Octojoin.

[satscraper]

It would be interesting to see a detailed Privacy level comparison between Coin Joins and Octojoin.

It would make more sense to compare Octojoin with Silent Payments rather than with CoinJoin, because the latter works by having multiple people build one transaction together, ^{which in turn involves their coordination with coordinator} while Octojoin ^{like SP} involves a single user dealing with multiple inputs that may carry  the negative history hallmarks. That said, in my view it is reasonable to assume that applying Octojoin after CoinJoin would increase the privacy level for users who might want to take such a complex approach.