Ad blocker interference detected!
Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers
Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.
Cipher level D was a Starfleet encryption code in use in the mid 2290s. It was broken by the Romulans between late 2295 and mid 2296. During the mission to Obsidian, after detecting a Romulan Warbird in the area, Commander Uhura of the USS Intrepid II ordered Lieutenant Duchamps to send a false message using cipher level D, embedded with a second message encoded using cipher level F. (TOS novel: Vulcan's Forge)