File Encryption is the only way to password protect any digital file. Any software which password protects your files uses some kind of encryption algorithm for encrypting your files. There are many trialwares like the Winzip and WinRar which encrypt your files with a password. However both of these are proprietary software and you need to pay after their trial period is over.
If you don’t want to use these or if you don’t trust some proprietary software to encrypt your confidential files then you can use open source alternatives like 7-Zip. Any open source software’s source code is peer reviewed by developers from around the world. They are developed keeping your most basic needs in mind and won’t bother you with nagging payment reminders.
7-Zip uses its own archive file format .7z for file encryption but it can also archive and extract files from other formats including ZIP, Gzip, bzip2, xz, tar and WIM.
You can use 7zip to create password protected 7zip files. Those files are encrypted using AES -256 bit encryption which is the most widely used and most secure encryption method. You won’t find a more secure encryption method than AES-256 as once you encrypt your files it’s nearly impossible to decrypt it without the password string.
Important things to Remember
Encrypting your file requires a password and even a strong encryption method like AES is of no use if you choose a weak password or don’t keep a track of your password after encrypting your files. If you lose your password it’s nearly impossible to decrypt those files.
You can read more about Advanced Encryption Standard (AES) on Wikipedia.
How to Encrypt Files using 7-Zip ?
Download and install 7-Zip. After installation 7-zip would add a link in the Context Menu.
Select the file or the folder which you want to password protect. Right click on the file and select
Add to archive…
This would open the
Add to Archive Dialog Box. Select Archive format as
Normal for Compression Level. Enter the Password in both the boxes and make sure that encryption method shows
AES-256. Check the check box for
Encrypt file names.
Press OK button to start the compression process. Once the compression ends a 7z archive containing your file would be created.
Now when you try to open or extract this file it would ask you for a password.
If you want your original unprotected file just right click the file and select
Choose the location for extraction. Enter your password and click on Ok to start your extraction process.