# Definitions

Based on these two basic generic notions, we have concepts related to our encryption protocols.

# SigningKey

A public/private key pair used by a user to sign and authenticate.

# EncryptionKey

A public/private key pair used by a user for encryption and decryption.

# Message

A Message is a document, an email, or a file of any kind that a user wishes to secure.

# MessageID

At the beginning of encryption, the Seald client makes a request to the Seald servers to assign to the Message a unique identifier called MessageID.

# MessageKey

This is the term used to designate the symmetric key required to decrypt a Message.

# EncryptedMessageKey

This is a MessageKey, protected using the public key of a file recipient. The recipient's private key is required to retrieve a MessageKey from an EncryptedMessageKey.

# EntrustedMessageKey

This is a MessageKey, protected so that only Seald servers can retrieve the MessageKey. This is used in case the recipient does not have the Seald solution installed, and therefore does not have a private key.