Data stored in a data storage system is hashed to generate a hash value. The hash value and a request for a time stamp are then sent to a time stamping authority. A time stamp token and/or a time stamp certificate is received from the time stamping authority. The time stamp token includes a time stamp and the hash value, and may be encrypted using a private key of the time stamping authority. The time stamp token and/or time stamp certificate is then stored with, for example, a reference to the data being stored in the data storage system. The time stamp token and/or time stamp certificate may then be used to validate the data being stored and the time stamp.