Dandelion++

[ghost]

Is your feature request related to a problem? Please describe.

• BIP 156 never got implemented in Bitcoin Core which could improve privacy: https://github.com/bitcoin/bips/blob/master/bip-0156.mediawiki

• Reasons: (TLDR: Denial of Service)
  Dandelion transaction relay (BIP 156) #13947 (comment)

  https://bitcoin.stackexchange.com/a/81504/

• Dandelion++ proposed for Bitcoin: https://arxiv.org/pdf/1805.11060.pdf

• Implemented in Monero: Adding Dandelion++ support to public networks: monero-project/monero#6314

Describe the solution you'd like
Implement Dandelion++ in Bitcoin Core and if it involves any risks, let's test, try to find solutions or workarounds.

Describe alternatives you've considered
Tor

Additional context
Not sure how much is this PR and associated project related to this issue:
#18038

Also there is no option to specify Tor for sendrawtransaction RPC command :
https://bitcoin.stackexchange.com/questions/99442/in-bitcoin-core-how-to-use-tor-for-broadcasting-new-transactions-only

[ghost]

Recently there were some DoS attacks on Monero. Details are mentioned in this blog post: https://sethsimmons.me/posts/moneros-ongoing-network-attack/

I have asked related question in Monero SE to confirm if these attacks could have been avoided without Dandelion: https://monero.stackexchange.com/questions/12599/could-recent-dos-attacks-be-avoided-if-dandelion-was-not-implemented

[ghost]

I have tried few things with dandelion in last few weeks including running v0.16..99 with https://github.com/dandelion-org/bitcoin/tree/dandelion-feature-commits (compile, experiment, check logs etc.)

Tried resolving conflicts to include dandelion in recent code: https://github.com/prayank23/bitcoin/tree/dandelion-test

Consulting few people IRL and online

Nothing works. I give up and I don't want to live with this everyday that could improve privacy in Bitcoin without Tor or i2p but I cannot contribute. Affects my mental health and other projects. I will close the issue. If anyone really interested to work on this please reopen or check two things:

1. How to implement this? https://bitcoin.stackexchange.com/questions/81503/what-is-the-tradeoff-between-privacy-and-implementation-complexity-of-dandelion/81504#comment112827_81504
2. Dandelion Lite. Don't want to tag people but AJ is working on it or at least did some research: https://twitter.com/ajtowns/status/1362636875140272130