When a VSAM relative record data set (RRDS) is enciphered, the record size of the output data set must be at least four bytes greater than the record size of the RRDS. (The extra four bytes are needed to prefix a relative record number to the output record.) Specify the record size of an output VSAM entry-sequenced data set through the RECORDSIZE parameter of the DEFINE CLUSTER command. Specify the record size of an output sequential data set through the DCB LRECL parameter in the DD statement of the output data set. When an enciphered RRDS is deciphered with a RRDS as the target, any empty slots in the original data set are reestablished. When a linear data set is enciphered, both the input and output data sets must be linear data sets.