A method begins by a dispersed storage (DS) processing module receiving a request regarding at least a portion of corresponding encoded data slices, wherein a collection of encrypted and encoded data slices of a plurality of collections of encrypted and encoded data slices includes a common data aspect, wherein encrypted and encoded data slices of the collection of encrypted and encoded data slices are produced by individually encrypting corresponding encoded data slices using a common encrypting character string and representations of the corresponding encoded data slices. The method continues with the DS processing module identifying the common encrypting character string of the corresponding encoded data slices. When the request is to delete the corresponding encoded data slices, the method continues with the DS processing module obfuscating the common encrypting character string in a local memory such that the collection of encrypted and encoded data slices are effectively incomprehensible.