# GlossaryΒΆ

- authentication
- The process of verifying that a message was created by a specific individual (or program). Like encryption, authentication can be either symmetric or asymmetric. Authentication is necessary for effective encryption.
- ciphertext
- The encoded data, it’s not user readable. Potential attackers are able to see this.
- ciphertext indistinguishability
- This is a property of encryption systems whereby two encrypted messages aren’t distinguishable without knowing the encryption key. This is considered a basic, necessary property for a working encryption system.
- decryption
- The process of converting ciphertext to plaintext.
- encryption
- The process of converting plaintext to ciphertext.
- key
- Secret data is encoded with a function using this key. Sometimes
multiple keys are used. These
**must**be kept secret, if a key is exposed to an attacker, any data encrypted with it will be exposed. - nonce
- A nonce is a
**n**umber used**once**. Nonces are used in many cryptographic protocols. Generally, a nonce does not have to be secret or unpredictable, but it must be unique. A nonce is often a random or pseudo-random number (see Random number generation). Since a nonce does not have to be unpredictable, it can also take a form of a counter. - opaque key
- An opaque key is a type of key that allows you to perform cryptographic operations such as encryption, decryption, signing, and verification, but does not allow access to the key itself. Typically an opaque key is loaded from a hardware security module (HSM).
- plaintext
- User-readable data you care about.
- private key
- This is one of two keys involved in public-key cryptography. It
can be used to decrypt messages which were encrypted with the
corresponding public key, as well as to create signatures,
which can be verified with the corresponding public key. These
**must**be kept secret, if they are exposed, all encrypted messages are compromised, and an attacker will be able to forge signatures. - public key
- This is one of two keys involved in public-key cryptography. It can be used to encrypt messages for someone possessing the corresponding private key and to verify signatures created with the corresponding private key. This can be distributed publicly, hence the name.
- public-key cryptography
- asymmetric cryptography
- Cryptographic operations where encryption and decryption use different keys. There are separate encryption and decryption keys. Typically encryption is performed using a public key, and it can then be decrypted using a private key. Asymmetric cryptography can also be used to create signatures, which can be generated with a private key and verified with a public key.
- symmetric cryptography
- Cryptographic operations where encryption and decryption use the same key.
- text
- This type corresponds to
`unicode`

on Python 2 and`str`

on Python 3. This is equivalent to`six.text_type`

.