There are three basic encryption methods: hashing, symmetric cryptography, and asymmetric cryptography. Each of these encryption methods have their own uses, advantages, and disadvantages. All three of these encryption methods use cryptography, or the science of scrambling data.

Cryptography is used to change readable text, called plaintext, into an unreadable secret format, called ciphertext, using a process called encryption. Encrypting data provides additional benefits besides protecting the confidentiality of data. Other benefits include ensuring that messages have not been altered during transit and verifying the identity of the message sender. All these benefits can be realized by using basic encryption methods.

The first encryption method, called hashing, creates a unique fixed length signature of a group of data. Hashes are created with an algorithm, or hash function, and are used to compare sets of data. Since a hash is unique to a specific message, any changes to that message would result in a different hash, thereby alerting a user to potential tampering.

A key difference between a hash and the other two encryption methods is that once the data is encrypted, the process cannot be reversed or deciphered. This means that even if a potential attacker were able to obtain a hash, he would not be able to use a decryption method to discover the contents of the original message. Some common hashing algorithms are Message Digest 5 (MD5) and Secure Hashing Algorithm (SHA).

Symmetric cryptography, which is also called private-key cryptography, is the second encryption method. The term "private key" comes from the fact that the key used to encrypt and decrypt data must remain secure because anyone with access to it can read the coded messages. This encryption method can be categorized as either a stream cipher or a block cipher, depending upon the amount of data being encrypted or decrypted at a time. A stream cipher encrypts data one character at a time while a block cipher processes fixed chunks of data. Common symmetric encryption algorithms include Data Encryption Standard (DES), Advanced Encryption Standard (AES), International Data Encryption Algorithm (IDEA), and Blowfish.

Asymmetric, or public key, cryptography is the last encryption method. This type of cryptography uses two keys, a private key and a public key, to perform encryption and decryption. The use of two keys overcomes a major weakness in symmetric key cryptography in that a single key does not need to be securely managed among multiple users. In asymmetric cryptography, a public key is freely available to everyone while the private key remains with receiver of ciphertext to decrypt messages. Algorithms that use public key cryptography include RSA and Diffie-Hellman.