user-1: What are the different trade-offs involved in options mentioned below that users should consider while using Tor/i2p in Bitcoin Core based on privacy and security?

Only Tor or i2p
1.1 onlynet=i2p
1.2 onlynet=onion

Tor/i2p and clearnet peers
2.1 Tor + ipv4/ipv6
2.2 i2p + ipv4/ipv6

Other combinations
3.1 Tor + i2p + ipv4/ipv6
3.2 Tor + i2p (onlynet=onion and onlynet=i2p)


I am not sure about using 3.1 or 3.2 which was mentioned in a tweet thread. IMO one of them (2.1 or 2.2) should be used. Still doing research and looking for articles that explain trade-offs.
1.1 and 1.2 should be avoided considering the trade-offs mentioned in https://github.com/bitcoin/bitcoin/pull/21157

user-1: 




Obsc location
Anon P2P
Bridge
Dissoc




Tor Only
Yes
Yes(Tor)
Yes(Tor)
Yes


i2p Only
Yes
Yes(I2P)
No
Yes


Tor+i2P
Yes
Yes
Yes(slow)
Yes


Tor+i2P+IPv4
No
Yes
Yes(fast)
No




https://www.reddit.com/r/TOR/comments/o5z4r1/tor_and_i2p_tradeoffs/h2sw202?utm_source=share&utm_medium=web2x&context=3
Basic differences between Tor and i2p: https://github.com/prayank23/Learning-Bitcoin-from-the-Command-Line/blob/i2p/15_0_Using_i2p.md

Only Tor or i2p


Tor/i2p and clearnet peers

The onlynet=onion configuration option can potentially ensure the node attempts to only
connect over Tor. It is more private when you combine it with no reachable IPv4/IPv6 address,
in particular if you want to broadcast transactions without them being correlatable with your IP.
Sybil Attacks
On the other hand, if you only make random Tor connections, you're much more vulnerable to Sybil attacks.
As Tor addresses may be created at no cost, an attacker can potentially flood the network with many Tor
nodes and receive all of the outbound Tor connections an onlynet=onion node makes.
This is significantly less a concern with if you make -addnode connections to trusted peers
(even if they're onion addresses). It's also alleviated with IPv4/IPv6 (especially when using the -asmap
configuration option) due to the cost of obtaining IPs in many networks.
If all of your connections are controlled by a Sybil attacker, they can easily prevent you from seeing confirmed
transactions  and, with more difficulty, even trick your node into falsely reporting a transaction as confirmed
on the blockchain with most cumulative “chainwork”.
Network Partitioning
If too many nodes use onlynet=onion, it could become difficult for onion nodes to communicate with clearnet nodes,
preventing the Tor network from seeing recent transactions and blocks. It is essential that some nodes access both
clearnet and Tor.
https://github.com/bitcoin/bitcoin/pull/22316/commits/2c18e7f6614d665f4eb9891f83391a5317e7d113

Tor + i2p + ipv4/ipv6

If looking for privacy, this may not be the best option however I don't see any security issues with this setup.

Tor + i2p

I would consider this as experimental for now and will update the answer if I find any issues.
For maximum privacy, it is preferable to disable accepting incoming connections.
Related Question: https://tor.stackexchange.com/questions/6930/tor-i2p-on-a-system-and-is-i2p-better-than-tor

-1: <p>What are the different trade-offs involved in options mentioned below that users should consider while using Tor/i2p in Bitcoin Core based on privacy and security?</p>
<ol>
<li><p>Only Tor or i2p</p>
<p>1.1 onlynet=i2p</p>
<p>1.2 onlynet=onion</p>
</li>
<li><p>Tor/i2p and clearnet peers</p>
<p><strong>2.1 Tor + ipv4/ipv6</strong></p>
<p><strong>2.2 i2p + ipv4/ipv6</strong></p>
</li>
<li><p>Other combinations</p>
<p>3.1 Tor + i2p + ipv4/ipv6</p>
<p><strong>3.2 Tor + i2p (onlynet=onion and onlynet=i2p)</strong></p>
</li>
</ol>
<p>I am not sure about using 3.1 or <strong>3.2</strong> which was mentioned in a <a href="https://twitter.com/StopAndDecrypt/status/1366754208012189698" rel="nofollow noreferrer">tweet thread</a>. IMO one of them (<strong>2.1 or 2.2</strong>) should be used. Still doing research and looking for articles that explain trade-offs.</p>
<p>1.1 and 1.2 should be avoided considering the trade-offs mentioned in <a href="https://github.com/bitcoin/bitcoin/pull/21157" rel="nofollow noreferrer">https://github.com/bitcoin/bitcoin/pull/21157</a></p>
 -1: <div class="s-table-container">
<table class="s-table">
<thead>
<tr>
<th></th>
<th>Obsc location</th>
<th>Anon P2P</th>
<th>Bridge</th>
<th>Dissoc</th>
</tr>
</thead>
<tbody>
<tr>
<td><strong>Tor Only</strong></td>
<td>Yes</td>
<td>Yes(Tor)</td>
<td>Yes(Tor)</td>
<td>Yes</td>
</tr>
<tr>
<td><strong>i2p Only</strong></td>
<td>Yes</td>
<td>Yes(I2P)</td>
<td>No</td>
<td>Yes</td>
</tr>
<tr>
<td><strong>Tor+i2P</strong></td>
<td>Yes</td>
<td>Yes</td>
<td>Yes(slow)</td>
<td>Yes</td>
</tr>
<tr>
<td><strong>Tor+i2P+IPv4</strong></td>
<td>No</td>
<td>Yes</td>
<td>Yes(fast)</td>
<td>No</td>
</tr>
</tbody>
</table>
</div>
<p><a href="https://www.reddit.com/r/TOR/comments/o5z4r1/tor_and_i2p_tradeoffs/h2sw202?utm_source=share&utm_medium=web2x&context=3" rel="nofollow noreferrer"><sup>https://www.reddit.com/r/TOR/comments/o5z4r1/tor_and_i2p_tradeoffs/h2sw202?utm_source=share&amp;utm_medium=web2x&amp;context=3</sup></a></p>
<p>Basic differences between Tor and i2p: <a href="https://github.com/prayank23/Learning-Bitcoin-from-the-Command-Line/blob/i2p/15_0_Using_i2p.md" rel="nofollow noreferrer">https://github.com/prayank23/Learning-Bitcoin-from-the-Command-Line/blob/i2p/15_0_Using_i2p.md</a></p>
<blockquote>
<p>Only Tor or i2p</p>
</blockquote>
<blockquote>
<p>Tor/i2p and clearnet peers</p>
</blockquote>
<p>The <code>onlynet=onion</code> configuration option can potentially ensure the node attempts to only
connect over Tor. It is more private when you combine it with no reachable IPv4/IPv6 address,
in particular if you want to broadcast transactions without them being correlatable with your IP.</p>
<p><strong>Sybil Attacks</strong></p>
<p>On the other hand, if you only make random Tor connections, you're much more vulnerable to Sybil attacks.
As Tor addresses may be created at no cost, an attacker can potentially flood the network with many Tor
nodes and receive all of the outbound Tor connections an <code>onlynet=onion</code> node makes.</p>
<p>This is significantly less a concern with if you make <code>-addnode</code> connections to trusted peers
(even if they're onion addresses). It's also alleviated with IPv4/IPv6 (especially when using the -asmap
configuration option) due to the cost of obtaining IPs in many networks.</p>
<p>If all of your connections are controlled by a Sybil attacker, they can easily prevent you from seeing confirmed
transactions  and, with more difficulty, even trick your node into falsely reporting a transaction as confirmed
on the blockchain with most cumulative “chainwork”.</p>
<p><strong>Network Partitioning</strong></p>
<p>If too many nodes use <code>onlynet=onion</code>, it could become difficult for onion nodes to communicate with clearnet nodes,
preventing the Tor network from seeing recent transactions and blocks. It is essential that some nodes access both
clearnet and Tor.</p>
<p><a href="https://github.com/bitcoin/bitcoin/pull/22316/commits/2c18e7f6614d665f4eb9891f83391a5317e7d113" rel="nofollow noreferrer"><sup>https://github.com/bitcoin/bitcoin/pull/22316/commits/2c18e7f6614d665f4eb9891f83391a5317e7d113</sup></a></p>
<blockquote>
<p>Tor + i2p + ipv4/ipv6</p>
</blockquote>
<p>If looking for privacy, this may not be the best option however I don't see any security issues with this setup.</p>
<blockquote>
<p>Tor + i2p</p>
</blockquote>
<p>I would consider this as experimental for now and will update the answer if I find any issues.</p>
<p><strong>For maximum privacy, it is preferable to disable accepting incoming connections.</strong></p>
<p>Related Question: <a href="https://tor.stackexchange.com/questions/6930/tor-i2p-on-a-system-and-is-i2p-better-than-tor">https://tor.stackexchange.com/questions/6930/tor-i2p-on-a-system-and-is-i2p-better-than-tor</a></p>
