Encryption is the ultimate expression of hate and discontent towards the Government as it prevents them from protecting you from yourself. Government is your friend, therefore, using encryption prevents them from reading your emails, looking through your files, or reading your furry fan fiction that you've been working on for the past year.
You encrypt a file or an email to ensure that only the appropriate receiver of the file or email is able to access it. Ways to decrypt the stuff is like putting in a password or using certificates.
If you're Smart, which you are not, you would encrypt your drive with Bitlocker (for those running Windows, or add an encryption key to GRUB to encrypt your filesystems (for Neckbeard Operating Systems]].)
Encryption protects you from sniffing attacks on the wire as all people would see is random gibberish. SSLv1.2 (the most widely used SSL implementation on the Internets) is not secure you moron, so don't even call SSL encryption anymore. If you want to protect yourself, use real encryption tools such as PGP or SSH to secure your VPN links to your stupid IRC server or use something with multi layer encryption such as Tor.
Basically, encryption pisses everyone off, because if you do it right, people trying to pwn your crap, to the Government law enforcement and Intelligence agencies won't be able to look into your crap. Not that anyone cares about you but you can feel special by pretending that the NSA has taken a special interest in you. So encrypt your crap.
Cryptography is commonly used by:
- The FBI
- l33t h4x0rz
Password123 -> SHA256 = 008c70392e3abfbd0fa47bbc2ed96aa99bd49e159727fcba0f2e6abeb3a9d601
ABCDEFGHIJKL Turns into BIKE -> NALW DNFPWEZXAJLR
Hiding Text or information within pictures.
ABCDEFG -> ROT1 = BCDEFGH