Preservation aware fixity in digital preservation

A computer based method for the monitoring of digital information in a data set, the method comprising:

• receiving a data set to be preserved, the data set including a plurality of preservation objects;
• creating a fixity table, the fixity table including one or more data types corresponding to preservation data types contained in the preservation objects, each data type being assigned an importance rank and one or more fixity functions;
• and
• for each preservation object, creating a Merkle tree corresponding to the preservation object and based on the fixity table, creating including:
• creating a root node for the Merkle tree which is associated with the preservation object;
• creating branch nodes from the root node for each portion of the preservation object;
• assigning an importance rank to each branch node;
• calculating a fixity value for each branch node based on and a fixity function stored in the fixity table;
• and
• storing the fixity value in an inner node connected to the branch node as a stored fixity value;
• receiving a fixity validation request;
• recomputing the fixity value for each branch node to form a recomputed fixity value;
• and
• comparing the stored fixity value to the recomputed fixity value to determine if the preservation object has been altered.