# What is Symmetric Encryption?

You will learn the terms encryption, encryption algorithm encryption key and symmetric encryption in this lesson.

Cryptography is the art and science of making data impossible to read. Cryptographic algorithms start with plain, readable data (plaintext) and scramble it so it becomes an unreadable ciphertext. Each encryption algorithm must also specify how the ciphertext can be decrypted back into the plaintext it came from, so that the intended recipient can read it.

Encrypting the plaintext to ciphertext will give high security to your confidential data and only the authorized person who is supposed to read this document, can read it.

### Encryption Terms

Following are some important terms related with encryption. Before continuing, you should know what these terms are.

__Plaintext:__ The information in its original form. This is also known as cleartext.

__Ciphertext:__ The information after it has been obfuscated by the encryption algorithm.

__Encryption:__ The process of changing the plaintext into ciphertext.

__Decryption:__ The process of changing the ciphertext into plaintext.

__Encryption Algorithm:__ An algorithm defines how data is transformed when original plaintext data scrambled to ciphertext. Both the data sender and the recipient must know the algorithm used for data transformation. The recipient should use the same algorithm to decrypt the ciphertext back into the original plaintext data.

__Encryption Key:__ A key is secret value, which is used as an input to the algorithm along with the plaintext data when plaintext is converted to ciphertext. The same secret key should be used to decrypt the ciphertext back into plaintext data.

__Cryptography:__ The art of concealing information using encryption.

__Cryptographer:__ An individual who practices cryptography.

__Cryptanalysis:__ The art of analyzing cryptographic algorithms for identifying the weaknesses.

__Cryptanalyst:__ An individual who uses cryptanalysis to identify the weaknesses in cryptographic algorithms.

### What is Symmetric Encryption?

Symmetric encryption is the process of converting readable data unreadable format and converting it back to readable format using same key. Symmetric encryption algorithms use the same key for encryption and decryption. The key must be exchanged so that both the data sender and the data recipient can access the plaintext data. The plaintext (Readable Text) is converted to ciphertext (unreadable text) using a key and at the receiving side the same key is used to covert back the ciphertext (unreadable text) to plaintext (Readable Text).