Abstract: After an introduction of the traditional fix method of digital data,in view of trusted forensics,a framework and its corresponding trusted fix method which supports the digital data's static properties is provided.Using DSA digital signature,timestamp,and the third confirmer signature scheme,the specific trusted fix algorithm of digital data is studied.Via formalized analyzing,the constraint rules for the digital data's static properties have been defined to be trusted,which also supports to the trusted fix.At last,with introduced axioms,theorems and rules,the formalized analyzing of trusted forensics is validated by certain examples.