"A nano-code for a specific lock. Your soft key “ring” (a list of soft keys currently stored by your software) can be viewed in your Datavault. Once a soft key is in your possession, you can open its associated lock at will. Since they are data, soft keys take up no physical inventory space."
Softkeys are collected by the player and stored in their datavault to open specific locks in Deus Ex: Invisible War. The softkey "ring" (a list of softkeys currently stored in the player's software) is the successor to the keyring from Deus Ex.