• Authors of Word macros can digitally sign their work to prevent tampering.Man Pressing the Red Stop Button - No text on Buttons. image by Andrew Brown from Fotolia.com
  
  A digital signature is an electronic certification that a computer object has (a) been authored by a particular person or entity, and (b) has not been modified since that person or entity digitally signed the object. Digital signatures can be used to sign macro code for Microsoft Word; users of the macros need to know that they can trust them to not damage their system or introduce spyware. There are several types of certificates that can sign Word macros, depending on the requirements.
  
  

Administrator

• System administrators issue PKI (public key infrastructure) certificates which ensure security. In addition to being used for code signing, these certificates can authenticate the identity of a user of the system and allow then to send secure, signed email.
  
  

CodeSigning

• A Certificate Authority issues these certificates using the CodeSigning template in a Windows domain. The recipient of one of these certificates must also be an individual user of the domain.
  
  

UserSignature

• A Certificate Authority issues these certificates to individual users. They can authenticate a user, and they can allow a user to send both signed and secure email via Microsoft Exchange.