Software to protect data

Keeping data secret from other can be just as important as keeping them safe from damage or destruction. Many file archive and compression programs, like WinZip, allow you to 'lock' your compressed archives with a password. A locked archive cannot be altered or opened without the correct password. Databases can also be protected by passwords. Access to the data will be denied without the correct password.
This is important for businesses. Microsoft Word allows you to add password protection to any documents you save, so that others cannot open or alter a file you save.
Microsoft Excel has several methods of protecting data in a spreadsheet. You can prevent others from opening and viewing a spreadsheet, or from altering any of its data

Encryption can be used as further protection of files. It is the process of altering data to make them unreadable or unusable to anyone who does not have the correct method to reverse the process.
One of the best and most widely used encryption systems is PGP (Pretty Good Privacy). There are similar programs.

Data encryption using PGP

Password or encrypted files are generally secure whether stored centrally or distributed. Password protected files cannot be altered or viewed without supplying the correct password. Encryption is an extra measure taken so that if password protection is breached, the encrypted document is not readable or useful unless decrypted.