TOPIC: Encrypting Files with 7- : Windows XP Software: 7-zip () Version: 4.65

Updated: 2/9/09

Contact: Tim Unten Email: [email protected] Phone: (808) 547-4891

Computer hackers have the ability to intercept and read electronic files/data that travel through the Internet via email or other programs/protocols. Encryption is a method to scramble the file data to render it unreadable to unauthorized users. Authorized users must enter a valid password to decrypt the file and make it readable again.

A. Download and Install 7-zip 1. Goto http://www.7-zip.org/download.html 2. Download the .exe type (for Windows XP). 3. Double click on the downloaded .exe file to run the installer. 4. Select all default settings and click Next until complete.

B. Encrypt Files Note: The 7-zip program makes a copy of your files, , and encrypts the copied files into a single password protected .zip file. The files in the encrypted zip file is read-only. Your original files will remain unaffected by this process. 1. Highlight the file(s) to encrypt 2. Right click the selection > 7-Zip > Add to Archive

3. Rename the Archive (This will be the filename of the .zip file that will be created) 4. Select Archive format to Zip 5. Enter a Password 6. Select an Encryption Method: a. ZipCrypto is a weak encryption protocol, but is conveniently accessible using the built-in Windows zip extraction tool. Use for moderately sensitive data. b. AES-256 is a strong encryption protocol, but files must be extracted using a 3 rd party program (e.g. 7-zip, WinZip). Users that try to use the built-in Windows zip extraction tool will not be prompted to enter a password nor be given any option to open the file. Use for highly sensitive data.

7. Click Ok 8. This will create an encrypted zip file in the same directory as the original files.

9. Send the encrypted zip file to your recipients. Note: Never send the password along with the encrypted zip file in an email message! Instead, use another means to transfer the password (e.g. Telephone).

C. Decrypt Files 1. If you selected the ZipCrypto encryption method in step 6 above, you may use the built-in Windows zip extraction tool: a. Right click the zip file > Extract All . b. Follow the prompts and enter the password. Note: The extracted files are not encrypted. 2. If you selected the AES-256 encryption method in step 6 above, you must use a 3 rd party zip program (e.g. 7-zip, WinZip) a. Right click the zip file > 7-zip > Extract Files b. Enter the password > Click Ok . Note: The extracted files are not encrypted.