Shadow depositories are the most secure storage facilities in the Uncharted Territories -- and perhaps in all of the Milky Way. As such, they are frequently used by criminals to keep their ill-gotten gains. As such, owners of shadow depositories -- such as Natira -- maintain a strict policy of discretion.
The security systems of shadow depositories are complex and multi-layered. Natira's was protected by automated guns, motion detectors, and armies of armed and heavily trained guards who scan everyone and everything routinely. Every inch of the depository, except inside storage containers, is observed from a central observation room. Inner doors are locked with codes that change frequently. Access to the vaults is regulated from the depositing room. Customers are designed codes based on their genetic makeup, so only they can only access their own containers. The vaults are lined with Maddium Steel. An average depository contains 30,000 storage vaults.
Another such depository, the Bank of Kabraxos, was perhaps even more heavily monitored. Even air consumption was closely measured, and DNA scans were required to pass through every stage of security. On top of this, the bank was guarded by a dangerous psionic creature called "the Teller" which could detect guilt and criminal intent in other beings -- and could liquify their brains.
Shadow depositories have only seldom been robbed. The first recorded robbery of a shadow depository was committed by the crew of Moya with the aid of a compliment of mercenaries and pirates. The Archive, found within the J Star Cluster, was broken into by RAC Team 25698-A, with the help of Fancy Lee and Khlyen.
Even as late as 3399 CE, shadow depositories were still commonly in use -- the Fenris Rangers used one located on Freecloud to store their financial resources.
Source[]
A shadow depository features in several episodes of the second season of Farscape. This also includes details from Doctor Who, Killjoys, and Star Trek: Picard.