What is Number Used Once
We often talk with you about various terms, technologies and concepts involved in cryptocurrency processes. And our review today will not be an exception – we will find out what the number nonce is. This knowledge alone will not bring you any exceptional benefit in working with digital currencies, but it will not be superfluous to fully understand the work of the blockchain.
A one-time number is a random or semi-random number that is generated for a specific use, usually associated with cryptographic communication or information technology.
The term itself means “a number used once” or “a one-time number”, and is most often referred to as a cryptographic one-time number. Typically, a one-time number is a value that changes over time to ensure that certain tags are not reused.
A one-time number can be a time stamp, a counter of visits on a web page or a special marker designed to limit or prevent unauthorized playback of a file.
Types of One-Time Values
A one-time number can be classified based on how it is generated, randomly or sequentially. A random one-time number is created by combining arbitrary numbers, while a sequential one-time number is created gradually.
Using the sequential nonce method ensures that values are not duplicated, cannot be reproduced, and are in place. However, using the random one-time number method protects against intruders much more reliably. Ideally, a one-time number should have both a random and a sequential component.
Use cases for a one-time number
One-time values can be used for various information technology applications, including:
- Authentication – Authentication protocols can use a one-time number to ensure that old messages cannot be re-processed. For example, ordering a product using an e-commerce site usually uses a one-time number to give the purchase originality. Without this, an attacker could potentially reproduce encrypted information as many times as needed to continue to place orders under the same name and with the same purchase information.
- Hashing Health check systems use one-time values to change the input to a cryptographic hash function. This helps to fulfill arbitrary conditions and get the desired complexity.
- Initialization – the initialization vector (IV) is a one-time number used to encrypt data. IV, applied only once in any session, and prevents the repetition of sequences in ciphertext. Detecting such repetitions can help an attacker crack a cipher.
- Identity management. You can use one-time values for user account recovery, two-factor authentication (2FA), or single sign-on (SSO).
- Electronic signatures. Secret disposable values are sometimes used by electronic signature tools to create, compare and verify signatures.
- Cryptocurrency – in some cryptocurrencies (Bitcoin, Ether), a one-time number is used to create a cryptographic hash that connects to the blockchain. In mining, a one-time number refers to a hash value that is lower than the target complexity.
- Asymmetric cryptography – in certain cases, public-key cryptography, as in the SSL / TLS protocols, exchanges two unique one-time values. One value is provided by the client and the other by the server, protecting each connection from attacks or interventions.
Nonce in cryptocurrency
Each transaction in the blockchain must have a one-time number, because it indicates the number of outgoing operations from a specific address. That is, every time you send funds, the previous one-time number is increased by 1 value. There are certain rules that govern the validity of transactions, and nonce is used to enforce some of these settings.
For example, this concerns the sequence – you cannot send a transaction with the number 1 until you send it with the number 0, or with the number 2 until you send 0 and 1, etc. This is really important, since the use of a one-time number is prevented by double expenses, since the number will always indicate the order of transactions.
In fact, the nonce number is one of the whales on which the blockchain rests. Its use guarantees order, security and protects, first of all, the owners of cryptocurrency assets.