1. A method for storing a data object, the method comprises: identifying a plurality of data segments of the data object; generating a plurality of key indexes for the plurality of data segments; for a data segment of the plurality of data segments: accessing data segment key information based on a corresponding key index of the plurality of key indexes to determine whether an encryption key has been generated for a similar data segment, wherein the encryption key is a representation of the similar data segment; when the encryption key has been generated for the similar data segment: using the encryption key to encrypt the data segment to produce an encrypted data segment; compressing the encrypted data segment to produce a compressed and encrypted data segment; and storing the compressed and encrypted data segment in a storage unit of a dispersed storage network (DSN).