How to digitally sign a MS Word document (Word for Mac)

There are many add-ins that provide a digital signature service in Word, including DocuSign, Adobe Acrobat Sign, Impression, and others.

1. On the Home tab click Add-ins.
2. Search for e-signature, select Add for the service you want, and follow the prompts.

That said, there is an important issue to understand when using digital signatures. NEVER allow a your handwritten signature to be used to authenticate any document. It is incredibly easy to make an exact copy of your signature and paste it to any document. If you ever allow a digital copy of your handwritten signature to be used to authenticate anything at all, you run the risk of being held to any document that bears a copy of your signature. You have no control whatsoever over your digital signature if you ever allow a picture or scan of your signature to be used for authentication purposes.

Instead, use a digital certificate that does not contain a copy of your physical signature to authenticate documents.

For example, Adobe products let you include your physical signature within a digital signature. DON"T DO THAT! Yet almost every tutorial out there tells you how to use your handwritten signature. Crazy!

Adobe also offers a free, secure way to sign PDF files using a digital certificate which you can create yourself. All you need is Adobe's free Acrobat Reader program from Adobe.com. This process works exactly the same in both Adobe Reader (free) and Adobe Acrobat (not free), so if you have either program you can do it.

In Word, use File > Save As and choose to save as PDF. Then open the PDF in Acrobat.

You need to make at least one digital signature file that can be used until it expires. You can make several signatures that you might use for different purposes, say one for work and another for personal use. They are easy to make.

Ignore the E-Sign and other signature options. In the left column look for Use a Certificate and choose that option. You may have to click the More button at the bottom of the list to see the Use a Certificate option.

Then, click the Digitally Sign option. You'll be prompted to drag a rectangle on your document where you want the digital signature to appear. Click OK and then use your mouse or keypad to draw a rectangle at the place in the document you want your digital signature to appear. Then, in the turquoise band that displays under the toolbar, click Sign Document.

The first time you use Acrobat there are no existing digital signatures. Once you make your signature(s) they appear in this dialog and you don't have to make another one. But for the first time, click Configure New Digital ID. In the next dialog choose Create a New Digital ID and then Continue.

In the next dialog you're asked where to save the certificate: either a file or your keychain. Most of the time choose Keychain, but if you need to carry your certificate around with you to use on other computers (say you're a lawyer, doctor, real estate broker or agent and need to have portability), you could save it to a file on a flash drive (just don't lose track of the flash drive).

In the following dialog you fill in the blanks. Use the default Key algorithm and Use Digital ID for Digital Signatures (although it can be used for other things, too).

Click Save and you'll be back at the beginning and you can choose the Digital ID you just made. Then click Continue.

The next dialog is where everyone seems to go wrong. For Appearance, choose No Graphic. This is where you could make the fatal mistake of incorporating a file that has a picture of your signature, which you should NEVER do. There are other options in this dialog you should decide upon before clicking Sign. For example, if you lock the document after signing, then no one else will be able to digitally sign or modify the document. This is good if you want to make sure no changes at all can be made to the file, but don't choose that if your document needs to be also signed by others.