doc: release note about I2P ElGamal sunset #35951

pull jonatack wants to merge 1 commits into bitcoin:master from jonatack:2026-08-i2p-elgamal-sunset changing 1 files +8 −0

jonatack commented at 9:49 PM on August 11, 2026: member

See discussion in #35696.
DrahtBot added the label Docs on Aug 11, 2026
DrahtBot commented at 9:49 PM on August 11, 2026: contributor



The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.



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For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/35951.



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ACK janb84, sedited

Stale ACK zzzi2p

If your review is incorrectly listed, please copy-paste <code></code> into the comment that the bot should ignore.
jonatack force-pushed on Aug 11, 2026
DrahtBot added the label CI failed on Aug 11, 2026
in doc/release-notes-35696.md:6 in 31530378b9
```
   0 | @@ -0,0 +1,8 @@
   1 | +### P2P and Network Changes
   2 | +
   3 | +Support for the legacy ElGamal (type 0) encryption type when creating I2P
   4 | +sessions is being sunset by the I2P network and will be removed from bitcoind
   5 | +on or before v34. Nodes using I2P with versions of Bitcoin Core earlier than v27
   6 | +(PR #29200) should upgrade to at least v27, as they will soon only be able
```
fanquake commented at 10:15 PM on August 11, 2026:

Why not the latest release, or one of the maintained branches? When v32 will be released, v27 will have been EOL for a year, and has multiple published CVEs.

jonatack commented at 2:21 AM on August 12, 2026:

Done, feel free to suggest a rewording. (Bitcoin Core v27 contained #29200 that alleviates the issue in question.)

fanquake commented at 2:20 PM on August 12, 2026:

feel free to suggest a rewording

should upgrade to a maintained version of Bitcoin Core (30.x, 31.x, 32.x).

jonatack commented at 3:08 PM on August 12, 2026:

Added those specific versions with must/should phrasing for clarity

must upgrade to at least 26.1, and should upgrade to a version still receiving maintenance updates (30.x, 31.x, 32.x)

fanquake commented at 5:16 PM on August 12, 2026:

Thanks, but I'm still not sure why we would mention these older versions? Saying must upgrade to at least 26.1 implies that we think it would still be safe/ok for a user to upgrade to 26.1, but I don't think it is? We only recommend users run the latest/actively maintained versions of our software, and in this case, 26.1 is known to be unsafe.

jonatack commented at 7:05 PM on August 12, 2026:

I've simplified it by dropping the upgrade part entirely. Users can draw their conclusions from the facts.
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jonatack force-pushed on Aug 12, 2026
jonatack force-pushed on Aug 12, 2026
DrahtBot added the label CI failed on Aug 12, 2026
DrahtBot removed the label CI failed on Aug 12, 2026

Type	Reviewers
ACK	janb84, sedited
Stale ACK	zzzi2p

in doc/release-notes-35696.md:6 in 732a87badf

   0 | @@ -0,0 +1,9 @@
   1 | +### P2P and Network Changes
   2 | +
   3 | +Support for the legacy ElGamal (type 0) encryption type when creating I2P
   4 | +sessions is being sunset by the I2P network and will be removed from bitcoind
   5 | +on or before v34. Nodes using I2P with versions of Bitcoin Core earlier than v27
   6 | +(PR #29200) should upgrade to at least v27 (and preferably the latest release or

janb84 commented at 1:00 PM on August 12, 2026:

The change was even backported tot 26.1 in #29209 so the upgrade can even be lower.

on or before v34. Nodes using I2P with versions of Bitcoin Core earlier than v26.1
(PR [#29209](/bitcoin-bitcoin/29209/)) should upgrade to at least v26.1 (and preferably the latest release or

jonatack commented at 3:05 PM on August 12, 2026:

Done, thanks.

janb84 commented at 1:01 PM on August 12, 2026: contributor

Concept ACK 732a87badfb2429f593d1bbd3e7ae90211a8781d

Given the recommendation of (one of the) i2p maintainers about sunsetting the usage of ElGamal, I think this is a good step into doing that.

But because of the low possible nodes affected (According to https://coin.dance/nodes there are currently 26545 nodes, of those nodes there are roughly 2514 nodes (<26.1) So ~10% of the nodes are affected, I do not have any I2P usage-data but given the popularity of i2p that is only a small subset of those 2514 nodes.)

I would suggest to even expedite the timeline to version v33
jonatack force-pushed on Aug 12, 2026
janb84 commented at 3:10 PM on August 12, 2026: contributor

ACK 558cf9fab12b626a949454d598945f99d209e0cd

LGTM.
jonatack commented at 3:12 PM on August 12, 2026: member

I would suggest to even expedite the timeline to version v33

(IIUC, there is no rush here, as #35696 islands legacy I2P peers in favor of quantum-resistant signatures, which bitcoin in general is not ready for yet. The urgency is for pre-v26.1 users of I2P (good catch, thank you) to upgrade.
zzzi2p commented at 4:58 PM on August 12, 2026: none

ACK 558cf9f

not expressing an opinion on the choice of release target, as I said in the other PR that's up to you folks.
doc: release note I2P ElGamal sunset 800ad9c3c0
jonatack force-pushed on Aug 12, 2026
janb84 commented at 8:28 AM on August 13, 2026: contributor
re ACK 800ad9c3c0c4cbd09653e7889bf981d7ed557759

changes since last ACK:
- rewording of the action needed by node runners on out-dated software
sedited approved
sedited commented at 8:53 AM on August 13, 2026: contributor

ACK 800ad9c3c0c4cbd09653e7889bf981d7ed557759
sedited merged this on Aug 13, 2026
sedited closed this on Aug 13, 2026
jonatack deleted the branch on Aug 13, 2026

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#35696 i2p: update leaseset encryption types

doc: release note about I2P ElGamal sunset #35951

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