bug: failed decryption of some e2ee messages

[daniel-w00]

Describe the Bug

Mobile app fails to decrypt some end-to-end encrypted messages despite correct login and password entry; issue persists after logout/reinstall, while web client works perfectly.

Steps to Reproduce

1. Login in the mobile android app
2. Enter your E2E password
3. Try to view encrypted messages

Expected Behavior

To be able to see every encrypted messages in the group chat history - which is possible on the browser

Actual Behavior

some messages are not encrypted

Rocket.Chat Server Version

7.12.0

Rocket.Chat App Version

4.68.2 chat.rocket.android

Device Name

Pixel 9 Pro XL

OS Version

Android 16

Additional Context

• I have spaces in my e2ee password - is this an issue?
• at beginning e2ee encryption worked without issues in the app

[batinay1337]

same issue in iphone 16, iOS 26.2

[Sarthaktanpure]

Hi @daniel-w00 , @batinay1337 ,

I’m Sarthak Tanpure, a student contributor preparing for GSoC 2026.

I’m interested in investigating this mobile E2E decryption bug on Android/iOS. Could you please confirm if it’s okay for me to start working on this issue?

Thank you!

[daniel-w00]

Hi @Sarthaktanpure
I only reported this issue as a user but I can provide more info if necessary

[Rohit3523]

Yes, you can provide more information about the bug and the steps, which will help us investigate the issue.

[daniel-w00]

I don't really know how I can describe it more.

I am in a big chat room with 100+ users where only about 5 people write messages.
I logged into the app again and entered the e2ee password but noticed that most messages are shown as not encrypted.

-The 7 messages since 1.7.2025 till now are encrypted and not readable
-some mesages prior to that are decrypted, some not

On the web ui, after entering the e2ee password all messages are shown and everything works perfectly.

Reinstalled the app and tried on other phone but it didn't help.

[diegolmello]

@daniel-w00 I think there's definitely an issue on mobile here, but it's quite hard to reproduce this specific scenario.
We'll try to reproduce it on our workspace, but we may not have the exact same issue.

If possible, send a test user to me on your workspace. I understand if it's confidential and you don't want to share, but it'll definitely help us fix your bug.

[daniel-w00]

Sorry, a test user won't be possible 😕

I only could send logs from my app or screenshots. I don't have access to the server, I am just a user there.

[diegolmello]

@daniel-w00 ok, we'll try our best to reproduce it.
If you have more info, please let us know.

[batinay1337]

I fixed it with rebuilding in Xcode.

[Sarthaktanpure]

Hi @daniel-w00, @diegolmello 👋

Thanks for the clarification.

@daniel-w00 If you’re able to share logs or screenshots from the mobile app (especially around message decryption or E2EE initialization), that would be very helpful. You can remove or redact any sensitive information.

In parallel, I’ll try to reproduce this issue locally on Android by testing E2EE with:

• passwords containing spaces
• large group chats
• older encrypted message history

I’ll update here if I find anything useful.