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: identifying, for a DSN memory using multiple IDA (Information Dispersal Algorithm) configurations simultaneously, a first IDA configuration with a highest security level relative to each of the multiple IDA configurations; generating a master key; encoding the master key with a secure error coding function to produce master key slices according to the first IDA configuration; storing the master key slices in the DSN memory using the first IDA configuration; and when storing data with a second IDA configuration having a security level lower than the first IDA configuration, retrieving the master key slices, decoding the master key slices to obtain the master key and encrypting the data using the master key.