Please add the ability to lock individual ChatGPT conversations with a separate password, PIN, or biometric authentication.
Chat history syncs across devices, which is normally useful, but some conversations contain highly private information that a user may want to keep in their account without making them accessible from every device where ChatGPT is already logged in.
Archiving isn’t sufficient because an archived conversation can still be accessed by anyone with access to the account. Deleting the conversation also isn’t a good substitute because the user may need to retain it.
Ideally, a user could select “Lock conversation” from the chat menu. Opening that conversation on any device would then require a PIN/password or re-authentication. The lock should sync with the account rather than merely locking the conversation on one device.
This would be particularly useful for conversations involving relationships, legal matters, finances, health, work, or other sensitive personal subjects.
An additional option to hide locked conversations from the normal chat-history list until authenticated would make the feature even more useful