Direct Messages: send to one Node, with acknowledgement #35

New Issue

2026-10-05T20:07:21Z

twisla commented

2026-10-05 20:07:21 +00:00

What

A message addressed to a single Node (CONTEXT.md: Direct Message), acknowledged by that Node, with retries until it is or we give up.

What's known

Addressed packets ask for an acknowledgement (want_ack), and the recipient answers with a routing packet.
Encryption is the open point. Older Meshtastic encrypted Direct Messages with the Channel key, readable by everyone on the Channel. Recent firmware uses public-key encryption between the two Nodes. ADR 0001 deferred that; the design round decides (#30, question 4). It needs a Curve25519 key pair, kept in NVS, never shown or logged, and the peer's public key from its node info.
Receiving Direct Messages starts in M4 (#26).

Questions

Which encryption do we send with, and what do we show when the two ends disagree?
How long do we retry, and what does the Messenger show meanwhile?
Where the private key lives, and what a factory reset does to it.

## What A message addressed to a single Node (CONTEXT.md: Direct Message), acknowledged by that Node, with retries until it is or we give up. ## What's known - Addressed packets ask for an acknowledgement (`want_ack`), and the recipient answers with a routing packet. - **Encryption is the open point.** Older Meshtastic encrypted Direct Messages with the Channel key, readable by everyone on the Channel. Recent firmware uses public-key encryption between the two Nodes. ADR 0001 deferred that; the design round decides (#30, question 4). It needs a Curve25519 key pair, kept in NVS, never shown or logged, and the peer's public key from its node info. - Receiving Direct Messages starts in M4 (#26). ## Questions 1. Which encryption do we send with, and what do we show when the two ends disagree? 2. How long do we retry, and what does the Messenger show meanwhile? 3. Where the private key lives, and what a factory reset does to it. ## Related ADR 0001, CONTEXT.md (Direct Message), #26, #34, #33, #30.

twisla added this to the M5 Mesh transmit milestone 2026-10-05 20:07:21 +00:00

twisla added the

concern/security labels 2026-10-05 20:07:21 +00:00

twisla added a new dependency 2026-10-05 20:07:21 +00:00

#34 Messenger: send text on a Channel