Some may think that they have no use for cryptography. They don't need to send any top secret messages to friends or business partners and they aren't participating in any shady business. What they don't realize is that cryptography is prevelent in almost any part of our online lives, without us even seeing it.
Any time we log into any of our accounts, whether it be facebook, our bank account or a knitting forum, our information is encyrpted so that anyone that might be hacking in can't see what your username and password is. Much of our private information is protected with layers of cryptography. While we may not participate in the encryption and decryption process, it is important to know how a company is keeping our data safe. Companies will often post what level of security they are using on your data. 2048 bit encryption is the current standard.
Today many different encryption algorithms are used. The standard of the US government is the Advanced Encryption Standard, or AES. This system uses a symmetric cipher, meaning both the key used for encryption and the key used for decryption are the same. Symmetric ciphers like this require the use of a key exchange. Today people use Diffie-Hellman as well as RSA to exchange keys. There are other key exchange protocols as well. To learn more about how AES works click here.