A self-authenticating encryptable font for creating secure documents. The document
onto which the font is printed includes a surface containing one or more transaction
fields such that transactional data from the font is printed within at least one
of these fields. The font includes human-readable characters that are defined by
a fill pattern made up of spaced marks and a patterned background. Security characters,
made up of one or more encryptable data elements, may also be included. The encryptable
data elements may be either fixed or randomly variable with regard to each human-readable
character, independent of the human-readable characters, or capable of alteration
by an encryption algorithm. The presence of the unique human-readable characters
and the encryptable data elements give the impression that the document on which
they are printed may be subject to security enhancements, while alterations to
the encryptable data elements by an algorithm can be used during the printing process
to incorporate additional security information into the document. A user wishing
to self-authenticate encrypted information incorporated into the encryptable data
elements merely passes the document through an appropriately-configured scanning
device, then compares the decrypted information with overt indicia on the document.
