Using Digital Signatures When email is signed with a digital signature, it provides a level of proof that the person using the email address sent the message. | Team LiB Using Digital Signatures When email is signed with a digital signature it provides a level of proof that the person using the email address sent the message. More importantly it also ensures that no one tampered with the message. A digital signature is a digital code that can be attached to an email message to uniquely identify the sender. Like a written signature the purpose of a digital signature is to guarantee that the individual sending the message really is who he claims to be. To be effective we need to be assured that a digital signature is not forged and there are a number of different encryption techniques that guarantee this level of security. Encryption is a more secure form of a digital signature and encodes the message so that only someone with the sender s secret key or password can read the message. Encrypted data is also referred to as cipher text. Every digital signature has two levels of signing a simple digital signature that identifies messages that have been tampered with and an encrypted signature that encodes the message and attachments so that only the person the message is sent to can read it. Before you can digitally sign your email you must obtain a digital certificate. Although many corporations provide digital certificates to their employees anyone can get one free or at a low cost from several Internet sites. Most certificates are issued for one year and must be renewed or reissued when they expire. If you use Outlook at work your employer might issue a digital certificate for you to use. The certificate is valid only when you send email using the address that s included in the certificate. If you use several email addresses you ll need a certificate for each address you want to use to send digitally signed messages. Don t routinely sign all of your messages especially on personal messages or those sent to mailing lists. Not all email clients can read signed messages. Reserve the use of digital signatures for important .
