1. A method for signing data, comprising: serializing a tree structure of data into a data stream, the tree structure including a plurality of branches, the tree structure further including at least one element identified as an exclusion area, the data stream excluding the exclusion area, wherein serializing the tree structure into a data stream comprises converting the tree structure of data into a horizontal series comprising a root node, the root node comprising a plurality of folders, the plurality of folders comprising a plurality of data files, wherein the series further comprises a marker written at the end of at least one of the plurality of data files, the marker indicating the beginning of at least one of a folder and a data file; creating a digital signature of the data stream; and including the digital signature in a document associated with the tree structure, wherein the digital signature is included in the document at a location that differs from another location in which is stored an old digital signature, wherein the old digital signature is associated with an older generation of digital signature creation functionality, wherein the digital signature is stored within a first element of a document file format and wherein the old digital signature is stored within a different element of the document file format to preserve the both the digital signature and the older digital signature in the document, wherein an older version of an application searches for the old digital signature in the different element of the document file format.