Signing Forms Digitally

Form Versions

A signature is assigned to the form version in which it was set. Each change that is made to a PDF form (such as any data entered in form fields) is saved as an attachment to the original PDF. The original form is retained. This means that the current version of a form consists of the original form and the attached change information. In Adobe Acrobat or Adobe Reader, you can display the corresponding version of the form for each signature. The document is then displayed as it was when it was signed.

Any changes to the data of this version invalidate the signature. If data is subsequently entered in the input fields, you are informed when the signature is checked. The check can be performed on the server or client side.

Server-Side and Client-Side Signatures

The same prerequisites apply as for certification.

More information: Certifying Forms

Client-Side Signatures

The following additional prerequisites apply to client-side signatures:

• To sign a form, you use Adobe Acrobat or Adobe Reader.

  Note

  For up-to-date information about the required Adobe Acrobat or Adobe Reader version, see SAP Note 834573 .

• To enable a user to set a signature when using Adobe Reader, the appropriate Reader usage rights must be set in the form. Any interactive forms created with Web Dynpro for Java or ABAP have Reader usage rights automatically.

• If the form is also certified, then the permitted changes must be set so that the certification is not invalidated when the form is signed.

  More information: Certifying Forms

Signing a Form

Set the signature in the signature field of the form

Depending on the signature fields used when the form layout is created in Adobe LiveCycle Designer, the form can function in one of the following ways:

• After the form has been signed, all form fields are then locked against further input. Nor can you set any further signatures. If multiple signatures are used, this guarantees that the last signature protects all previously entered data and signatures from being deleted from the form.

• After the form has been signed, only form fields are locked against further input of data. You can still enter data in any signature fields in the form. This enables you to set further (multiple) signatures.

• In both previous options, it is possible to exclude input fields from being locked. After the form has been signed, only certain input fields (individual fields or groups of fields) are then locked against further input or changes.

  Note

  You can set Adobe Reader so that the fields that are ready for input in a form are highlighted.

You can sign a form on the server or client side.

• Signing a form on the server side

  When you sign a form on the server side, you may be prompted to specify the name of the certificate. However, the application can also select the certificate automatically; this means that the end user does not need to access the certificates.

• Signing a form on the client side

  To set a client-side signature (that is, your personal signature), use Adobe Acrobat or Adobe Reader and your own certificates.

Checking a Signature

You can check whether the signature of a form is valid or invalid. If a form contains multiple signatures, the check gives you a result for each signature.

• Checking signatures on the server side

  You can use this function if your application provides server-side checks on signatures in forms. The result of the check is a message about the status of the signature.

• Client-side signature check by the end user

  In Adobe Acrobat or Adobe Reader, you can display information about signatures in the form and their validity.

More information: Invalid Digital Signatures in Forms