Phasing cloaking device The phasing cloaking device was an experimental technology developed by a secret group in Starfleet Security in the 2350s . An expansion on the more traditional cloaking device , it was designed to phase sequence the structure of matter and energy to such a rate that it was possible to allow any vessel utilizing the device to pass through normal matter in the phased state . A direct violation of the Treaty of Algeron , which banned cloaking technology aboard Federation starship s , the phasing cloak was first tested aboard the in 2358 , under the command of Captain Erik Pressman . In response to the illegal use of this device , the crew of the " Pegasus " mutinied against Pressman , forcing Pressman and a small group of officers who sided with him , including a young Ensign Will Riker , to flee the ship . The cloak blew out the plasma relay s aboard the ship , and it drifted into an asteroid field in the Devolin system while still in a phased state . When it passed through a particularly large asteroid , the cloak failed , causing the " Pegasus " to partially materialize inside solid rock . The crew dead , the " Pegasus " remained entombed in the asteroid for the next twelve years , though the device itself survived . A Judge Advocate General ' s investigation into the mutiny was initiated , but , in order to conceal the illegal test , Starfleet Intelligence classified the file . In 2370 Pressman , then an admiral at Starfleet Intelligence , boarded the and mounted a mission to retrieve the cloaking device . He was successful , but not before a Romulan Warbird sealed the " Enterprise " inside the asteroid . Riker , then the first officer of the " Enterprise " , decided to reveal the existence of the device to Captain Picard in order to use it to escape the asteroid . This plan worked , and Picard subsequently ordered the " Enterprise " to decloak in front of the Warbird , thereby revealing the existence of the phasing cloaking device to the Romulans . Both Admiral Pressman and Commander Riker were subsequently taken into custody for their respective roles in the illegal experiment . ( ; ) Other similar phasing technology . In 2368 , on Devidia II , crew of the USS " Enterprise " - D devised a method of phase - shifting crewmen to a positive phase variance of 0 . 004 percent . Data was enveloped in a contained subspace force field created by a subspace generator . By adjusting the synchronic distortion of the field with the phase discriminator in his positronic brain , he phase - shifted himself . The procedure was repeated for other members of the crew using a tricorder modified to interface with the subspace generator , containing a custom built phase discrimination . It was theorized in both instances that the phase displacement was not precise enough to synchronize the " Enterprise " crew to the Devidians ' perceptual range , even though the " Enterprise " personnel could see them when phased . ( ) To covertly conduct their invasive experiments on other humanoid s , the Srivani also used this type of stealth technology for themselves , as well as their equipment and ships . In 2374 , when invading the USS " Voyager " , the technology hid the Srivani to a phase variance of 0 . 15 . Adjusting the Borg sensory node of Seven of Nine for this variance allowed her to see them . Seven also modified her hand phaser to a modulation that would penetrate the cloak . ( ) Both Klingons and Romulans have been experimenting with similar technologies , with the Klingons apparently forced to cease their experiments due to numerous accidents . ( )