Phase cloaking

The interphase cloaking device was an advanced type of cloaking device that allows a starship to travel through solid matter and high-energy fields. A molecular phase inverter moves the ship out of phase with the spacetime continuum.

In 2358, a branch of Starfleet Intelligence illegally developed such a device in direct violation of the Treaty of Algeron, which explicitly banned the Federation from developing cloaking technology.

The illegal actions and the fact that it was refered to as "a secret division of Starfleet Intelligence" implies that the 'branch' was Section 31.

A test aboard the USS Pegasus was initially successful, but the failure to maintain a steady temperature of the plasma intercoolers onboard the ship led to an explosion in engineering and later the crew, angry at the breach of the treaty, mutinied against the Captain, Erik Pressman. Starfleet Intelligence attempted to cover the incident up, but the truth was revealed in 2370 when Pressman attempted to recover the device.

Several other races have either experimented with, or utilize interphasing technology:

   * The Romulans were experimenting with an Interphase generator to create an interphase cloak. The experiment failed, heavily damaging the vessel on which the experiment was being run. The Klingons too experimented with interphase cloaking technology in the early 2360s but they abandoned their research due to several accidents.

   * Interphase technology was used extensively by the Srivani to hide their scientific experiments.

   * The Voth also used interphase cloaking technology.