Digital Signing

You can sign your document digitally just as you sign your paper document using a pen. The difference is the signature will be in digital form called a digital signature. You digitally sign a document using your secret key instead of using a pen.

Comparing to the usual signature you have on a piece of paper, digital signature cannot be forged. This makes the verification of a digital signature much easier than the verification of a signature on paper. You don't have to guess when it is hard to discern. You don't need an expert to do the work for you.

There are several methods of digital signing. The normal method is to take a digital document and sign it to produce a single, scrambled output that combines the input document and a digital signature. This output can then be sent to its recipient for verification. Once the digital signature is verified, the original document, assured to be authentic from the signer, can be extracted from the same output file. This is the easiest method to manage.

If your original document is in pure text form, you may choose to "Clear Sign" the document. Clear signing also produces one single output but the original content will not be scrambled so that it will still be readable and the extraction of the original document from the output becomes unnecessary.

If your original document is in binary form, you may want to "detach sign" it so that your original document is not touched. "Detach sign" produces an output that only contains a digital signature, which is not attached to the original document. For this reason, when you detach sign a document, you need to send both the original document and the detached signature to anyone who needs to verify your signature. Of course, extraction of original document is unnecessary because you are supposed to send the original document along with the detached signature.

From the main menu, choose "Privacy > Sign" to enter this screen. Once entered, you will be presented with a form to enter necessary data to sign:

On the toolbar, there are two buttons -- Accept and Start Over. Start Over button is used to clear out the form if you do something wrong and want to start over. Accept is used to start the signing process after you have filled out the signing data form. Your secret key is needed for signing. For this reason, you will need to provide your passphrase to unlock your secret key when needed.

Once the signing is done, the output will be saved into a file if you have specified one. At the same time, the output will also be sent to the data area.

After getting the output, you can either cut and paste or attach the output file through e-mail to send it to anyone you want to verify.