System and method for authenticating data using incompatible digest functions

A method, comprising:

• locating a first digest result and a second digest result in a file, said file including data of interest, and said first digest result and said second digest result undeceptively identifying said data of interest;
• creating, using a first digest function, a first digest of said data of interest, said first digest function being identical to a digest function used to create said first digest result;
• creating, using a second digest function that is incompatible with said first digest function, a second digest of said data of interest, said second digest function being identical to a second digest function used to create said second digest result;
• and
• comparing said first digest and said second digest with said first digest result and said second digest result respectively to create a match of the digests to undeceivably authenticate said data of interest:

A method of marking, comprising the steps:

• identifying data of interest in a data file;
• creating, using N digest functions, N digests of said data of interest;
• wherein said N is at least two, and said N digests undeceptively identify said data of interest;
• and
• appending said N of said digests to a file holding said data of interest to create said file including said N digests and said data of interest.