Techniques are described that generally relate to methods for detecting encryption status of a data file or data stream and selectively encrypting the data file or data stream based on the encryption status of the data file or data stream are generally disclosed. Example methods may include one or more of reading the data file or data stream from a data source, calculating a value of a property of the data file or data stream, comparing the calculated value with a threshold value to determine whether the file is encrypted or unencrypted, and encrypting files that are determined to be unencrypted.