Data encryption is a process of transforming plaintext, data that can be read by anyone, to cipher text. The encrypted data can only be read by someone with a secret decryption key. So someone can get hold of your file/data, but without a decryption key or tool, he or she would not be able to read it.

The Advanced Encryption Standard (AES) is the encryption standard used by the U.S. government and also it is one of the most popular algorithms used in symmetric key cryptography. This standard is the first publicly accessible cipher approved by the National Security Agency (NSA) for classified information up to the highest level of security.