A nonce, which stands for “number used once,” is a large and unique random number (or other data variable) that is only used once. Nonces are used to prevent misuse or malicious attacks when requests are made over a non-secure channel, such as HTTP. The longer a nonce is, the more difficult it will be for attackers to decipher and use.

A SmartVault nonce is a twenty-two character long string which can consist of capital or lowercase letters, numbers, dashes, and underscores. A nonce is created by sending a request to SmartVault’s REST API. A nonce is used to begin the authentication process with the SmartVault service. Once you are in possession of a nonce, you can use it to form a self-signed token, which is later used to request a client token. 

Although SmartVault nonces do not have a lifetime, they are ultimately used when creating a client token, which have an expiration time.