The Signature Appearance Is Only a Claim

Name or other information, such as signing time, which appears in the document does not in itself necessarily proof of identity, etc. The information is placed in the appearance document signed In the case of Acrobat signer. The features of electronic documents generally have to be able to represent the information in any form , it will not be possible to ensure that every appearance is automatically created and can not be forged by the signatories of the document. 

This fact does not underestimate the importance of the appearance of the signature to provide a means for a signatory to indicate intent when applying signatures. If you are looking for electronic sign then make an online search.

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The fact that the appearance is under the control of the authors mean that it directly represents the intention of the signatories. Appearance signature should be considered as distinct from a digital signature associated with the display and provides the means to verify its authenticity.

Signature visual appearance should be verified against the Digital Signature

Digital signature associated with the appearance of the signature should be used to verify that the signature is authentic appearance As a digital signature created using a certified key, known to belong to people identified, can be used to verify the authenticity and integrity of documents signed. However, because the digital signature is not visible, and do not appear directly in the document, it can not be used to show intent through appearances in the document.

Verification of signatures against the appearance of a digital signature can be done visually when reading the document with the signature verification information display. Readers can visually inspect the verification of the signature information as it appears in the document.