摘要 |
A method for safeguarding an electronic document includes inserting at least one digital signature image into the electronic document and generating a first check sum for the electronic document, with or without optionally-inserted biometric signature data, using a first hash function. A second check sum is then generated using a second hash function. The first check sum and the biometric data, if provided, are then symmetrically encrypted using a key that is the sum of the second check sum and a generated random value. The symmetrically-encrypted first check sum is attached to the document. The random value is then asymmetrically encrypted using a first public key of a first key pair and the asymmetrically-encrypted random value is added to the document.
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