Encrypt your Email

Well, we know that email is inherently insecure. But, what if we need to email an attachment that should be kept safe. Fortunately, there is a very easy approach to this which uses free software built-in to Windows XP computers. Simply convert the attachment(s) to a password-protected zip file. The process of creating the password encrypts the attachment. The email recipient can only open the file if they know the password. Careful, though, given time and determination a hacker could probably view the contents of your file. This is one simple step that will help keep your attachments secure. To see the specific steps, view the full text of this article.

PASSWORD PROTECTED ZIP FILES

Probably the easiest method to quickly secure an email attachment is to simply convert it to a password-protected zip file.  The resulting file is encrypted, and uses the password as the key.  Thus, the recipient must know the password to unzip the file and read it.  The advantages to this method are

•    it works with any file type
•    you can include many files in one zip file
•    no special software is required by the email recipient (because Windows XP comes built-in with the necessary software)
•    no keys need to be exchanged between the sender and the recipient (except of course the password)
•    it is quick and easy to implement
•    cross-platform compatible

As a note of caution: the encryption in zip files can be broken with time, determination and the proper tools.  So, understand that this is one level of security, but it is not fail safe.

We will walk through the zip creation process with screen shots using Windows XP.  In our example, we have a licensing agreement created in Microsoft Word.  The first step is to open Windows Explorer and simply right-click on the document and select Send To -> Compressed (zipped) Folder, as shown in Figure 1 below.

Now, you will see two files in Windows Explorer, the original agreement.doc Word document, and the agreement.zip file.  Currently, the Zip file is not encrypted.  To encrypt the Zip file, create a password by double-clicking on the agreement.zip file, and then selecting Add a Password…, as shown in Figure 2 below.

You will be asked to enter a password as shown in Figure 3 below.

Using complex passwords is best (passwords that are long and contain numbers and special characters).  Now, the Zip file is encrypted.  When sending your email, attach the Zip file.  The recipient will be prompted for a password in order to open the file.

[portions originally published in Orange County Lawyer Magazine]