Abstract: According to the invention, a digital document is protected through: receiving (11) the digital document; receiving (12) associated data comprising at least partially data from the digital document; creating (13) a hash of the associated data; asymmetrically encrypting (14-15) the hash with a private key to generate a digital signature; encoding (16) in a machine-readable code the digital signature and the associated data; and recording (17) the machine-readable code onto a resulting hardcopy. The authenticity of a printed hardcopy of the digital document can be verified through comparison (31) of data extracted from the printed hardcopy (21) with the associated data decoded (23) and verified (24-30) from the machine-readable code.

Abstract: A method and system of providing external transaction protection for a database using the database log or journal. The method involves creating a set of transaction templates which define transactions, using the templates to determine whether each record or entry in the journal represent part of a transaction, and maintaining a set of index file indicating transactions in progress. Each transaction template contains a number of filenames identifying files in the database affected during the transaction defined by the template. Each template also contains a key value representing one or more data fields in the database included in every action performed during the transaction. For each entry in the journal, a determination is made whether the entry belongs to a transaction based on the data fields represented in the entry and the key values associated with the templates.