1. A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method comprises: receiving a data access request for at least one data segment stored in the DSN; identifying a vault associated with the data access request and one of a plurality of sub-vaults associated with the vault including: issuing a plurality of requests to a set of distributed storage and/or task (DST) execution units to retrieve at least one set of vault list slices that are distributedly stored in the set of DST execution units, wherein a decode threshold number of vault list slices are needed to recover a vault list; receiving at least the decode threshold number of vault list slices in responses to the plurality of requests from the set of DST execution units; decoding the at least the decode threshold number of vault list slices to produce the vault list; and identifying the vault based on the vault list; retrieving access information corresponding to the one of the plurality of sub-vaults to determine whether the data access request is allowed; and when the data access request is allowed, retrieving a sub-vault directory associated with the one of the plurality of sub-vaults to identify a DSN address corresponding to the data access request, and fulfilling the data access request based on the DSN address.