1. A method of dynamically choosing a time to encrypt a copy of data created from data included in an original data set, the method comprising: receiving information related to a completion time of a data storage operation starting before a first time and required to be completed before the first time, wherein the data storage operation creates copies of at least a portion of the original data set; estimating a modified completion time based on the completion time and based on a time required to encrypt the created copies of the at least portion of the data set; and when the modified completion time occurs after the first time, encrypting data contained in the created copies after creation of the copies; and when the modified completion time occurs before the first time, encrypting data contained in the created copies during creation of the copies.