Digital Signatures in Forms 

Use

Signatures can be used in forms on both the client side and, if implemented by the application, on the server side. A client-side signature gives the end user the option of signing a completed form in a signature field. A signature refers to the entire form at the time it is signed and guarantees the integrity of all data in the form. A signature is assigned to the document version in which it was set. 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 made on the server side or on the client side.

Integration

See the section Integration in Form Certification and Digital Signatures.

Prerequisites

Server-Side and Client-Side Signatures

The same prerequisites apply as for certification.

Client-Side Signatures

The following additional prerequisites apply to client-side signatures:

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

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. For more information, see Features in Certification of Forms.

Features

Signing a Form

You set a signature in a form in a signature field. If a form contains multiple signature fields, then multiple signatures are possible.

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. The developer of the form determines which of these methods is used:

·        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.

You can set Adobe Reader so that the fields that are ready for input in a form are highlighted.  For more information, see the online help for Adobe Reader.

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

·        Signing a Form on the Server Side

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

·        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. For more information, see the online help for Adobe Acrobat or Adobe Reader.

 

Checking the 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

This function is enabled if your application implements 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

You can display information about signatures in the form and their validity in Adobe Acrobat or Adobe Reader. For more information, see the online help for Adobe Acrobat or Adobe Reader.

 

For more information about signature checks, see Scenarios for Setting and Checking Multiple Signatures.