WASHINGTON — Facebook wants to offer users more privacy in one-to-one discussions, and is testing a more secure type of Messenger conversation.

A small number of users currently have the option of switching to “secret conversations” — conversations that are encrypted end-to-end, meaning that even Facebook can’t read them, TechCrunch reports.

In a Facebook blog post, the company says it is using the open-source Signal Protocol, developed by Open Whisper Systems.

Other security layers include the ability to set a countdown timer that makes a message self-destruct after a certain amount of time. Also, the messages can only be read on one of the devices belonging to the message recipient.

Facebook suggests the extra security would be useful in discussing private information, including illness, or when sending financial information to your accountant.

The encrypted chats will not enabled by default; instead, a Messenger user will be able to start a secret conversation by tapping on a friend’s name, then clicking on “Secret Conversation.”

The sender can select how long until the message expires, ranging from 5 seconds up to 6 hours.

Facebook says it will make the feature available to more users over the summer.