Certifying Forms and Signing Digitally 
SAP supports the following security functions for Adobe-based forms:
Certification – Identifies the form author to secure the form layout against changes
Digital signatures – Identifies the form sender to secure the form data against changes
Unpermitted changes invalidate the certificate and the signature, and are therefore easily detected. A signature or certificate relates to invisible and hidden fields of a form, and to the comments, notes, and highlights they contain.
Recommendation
The use of digital signatures is governed by specific national rules. We recommend that you check the implications of the existing legal regulations for your form application scenarios on a regular basis.
Server- and Client-Side Security Functions
You can set a certificate or a signature for a form as follows:
Server-side (done by application)
Example: Digital signature of form-based invoices sent electronically
The required key pairs from the public key (part of a certificate) and the private key (credential) are in the J2EE Engine.
More information:
Adobe Document Services Configuration Guide (in English)
Client-side (done on the user PC in Adobe Acrobat or Adobe Reader)
Example: You sign an order form using the signature field created by the form developer.
The required keys are on the user's PC.
More information:
Online help for Adobe Acrobat or Adobe Reader
SAP Note 834573
More information: Public-Key Technology
Procedure
To protect against unpermitted changes to the form layout, certify your form and define the permitted change options.
More information: Certifying Forms
To ensure the integrity of the form data, set digital signatures.
More information: Signing Forms Digitally
Note the special procedure for handling hyperlinks, dynamic content, or JavaScript when signing or certifying forms.
More information: Hyperlinks, Dynamic Content, and JavaScript in Forms