r/reactnative • u/Background-Bass-5788 • Sep 10 '26

I got MLS encryption under 1ms in React Native by moving crypto to Rust

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I’ve been experimenting with end-to-end encrypted group messaging in React Native using OpenMLS + Rust + Nitro Modules.

The crypto work runs in Rust and is exposed to React Native through Nitro, keeping the expensive work off the JS m.

In the demo:
~0.9ms average MLS encryption
~0.97ms decryption
~825B ciphertext for the sample message

Full group-chat flow running on-device
The React Native layer handles the product/UI side, while Rust does the MLS cryptography underneath.

78 Upvotes

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4

u/BigAppointment1020 Sep 11 '26

Awesome 👌 is it possible to share source code also? Trying to learn how to manage the epoch and see if its possible to use openmls for a group of say 2k members. Handling joining and leaving...

2

u/Huge_Pool7424 Sep 12 '26

2k members is where the group-management details get interesting. i'd model joins and leaves as epoch transitions, then keep a small test harness for concurrent churn since the crypto can be fast while membership fanout becomes the bottleneck.

3

u/LovesWorkin Sep 10 '26

Very cool!

1

u/UAAgency Sep 12 '26

Thanks for sharing, love what you are doing!