Abstract
Quantum-resistant blockchains refer to cryptographic processes that are resistant to attacks via quantum computers. Present public-key algorithms depend on the difficulty of deciphering the discrete log and factorization problem of large prime numbers. Shor's algorithm can be used to break the hash signatures by quantum computers. Therefore, it is necessary for the development of a post-quantum secure signature scheme or quantum-resistant blockchain for post-quantum blockchain security. This chapter will discuss the impact quantum computers are predicted to have on public key cryptography based on the following topics: quantum computers, public key cryptography, quantum threat to PKI, Shor's and Grover's algorithms, post-quantum cryptography, and quantum-resistant blockchain.
TopStructure
This chapter discusses the following topics:
TopObjectives
At the end of this chapter, the following should be well understood:
- i.
The Blockchain Technology with its driving principles
- ii.
Pre-quantum cryptography
- iii.
Quantum blockchain and the threat it poses
- iv.
The implication of blockchain systems on quantum computers
- v.
Quantum-resistant blockchain. The various attributes that enable it to be secure
TopBlockchain: What It Is
Blockchain is a distributed open ledger that may effectively, permanently, and verifiably record transactions between two parties. It is an append-only database system that is transparent and includes the methods for obtaining consensus on data across a vast, decentralized network of agents with a low level of trust in one another.
It is a distributed database of records that is structured as a list of ordered blocks, where the committed blocks are absolute, the data is shared across a network of computers, and unlike a traditional database, which stores the data on a server, it does not provide a single point of vulnerability. It is distributed in the sense that the database is identical on each of its nodes (Allende, M., López, D.,et al., 2021). Data is stored in the form of transactions on a blockchain, which can represent everything from physical assets like houses and cash to intangible ones like patents, virtual transaction entities, or services.
Figure 1.
The basic fields of blockchain applications
Key Terms in this Chapter
Proof of Work (PoW): By making the process of mining, or recording transactions, challenging, Proof of Work is the mechanism that enables the Bitcoin network to remain stable. It is the blockchain network's initial consensus algorithm.
Authentication: Is used by a client to verify that the server is what it purports to be.
Malicious Transactions: Include any type of fraud, identity theft, or hacking done with the purpose of gaining an unfair advantage or benefiting from deceit.
Classical Blockchain: Is a traditional blockchain, the most basic level, a digital log of transactions kept on numerous computers (referred to as nodes) connected by a network.
Cryptography: Is the method of securing information and communication based on mathematical principles. It is a technique for protecting crucial data from unauthorized access.
Blockchain: Is a distributed, duplicated digital ledger of all transactions that run via the network of computers on the blockchain.
Quantum Secure Direct Communication (QSDC): Is a significant quantum communication protocol, that uses a direct conversation between communicating parties rather than the production of secret keys beforehand to send confidential information. Without the use of a private key, confidential information can be sent directly through a quantum channel.
Peer-to-Peer: Is the direct transfer of a resource, like digital money, between parties without the involvement of a centralized authority.
Asymmetric Encryption: Also known as public-key cryptography is a method of encrypting and decrypting data.
Superposition: Is one of the characteristics that set a quantum computer apart from a conventional computer. Users can tokenize, trade, and profit from their potential future income using this decentralized fixed income protocol.
Quantum-Resistant Ledger: Is a decentralized communication layer and post-quantum value storage that addresses the threat that quantum computing will bring to cryptocurrencies in the future.
Logic Computations: Blockchain transactions can be linked to computational logic which is, in essence, programs due to the ledger's digital character, so users may create formulas and guidelines that initiate transactions between nodes automatically.
Quantum Key Distribution: QKD is a safe way to exchange encryption keys that are only known to shared parties, which may be used to encrypt and decrypt messages. Quantum physics is used to ensure communication security.
Algorithm: Is a method for solving a problem that involves searching a database that is carried out step-by-step on a quantum computer.
Bits: Is a commonly used subdivision or unit of a single Bitcoin.
Node: Is one of the machines running the blockchain's software to verify and preserve the whole history of transactions on the network is referred to as a node.
Public Keys: Make it possible for cryptocurrency transaction execution. It is paired with a private key and a cryptographic code and employed to transfer cryptocurrency to a wallet.
Private Key: Like a password, is a secret number that is used in cryptography. In cryptocurrencies, they are also employed to verify transactions and establish who owns a blockchain address.
Hash: Is a function that takes an input string of any length and outputs an output of a defined length, satisfying the encrypted requirements necessary to complete a blockchain computation.
Decentralized Database: Is a hybrid of a regular database and a distributed database, supported by many layers of blockchains and using a database interface or compute interface for data recording and transactions.
Shor's Algorithm: Is a practical polynomial quantum technique for the factorization of integers that is tuned for finding prime factors in a hypothetical quantum computer.
Blockchain Systems: Is a method of storing data that makes it difficult or impossible to alter, tamper with, or trick the system.
Secure Hashing Algorithm (SHA): Is used for hashing data and certificates, designed to safeguard data.
Intrusion: Is the occurrence of an unauthorized user obtaining data or access permission that they are prohibited from.
Hacker: Is someone who utilizes computers to obtain data without authorization or one who steals from a vulnerable entity.
Binary Computers: Are computers that express messages, computer processor commands, and other types of data using a two-symbol system based on numbers, “0s” and “1s.”
Post-Quantum Cryptography: Aims to create cryptographic systems that are resistant to both quantum and conventional computers and are compatible with current networking and communications protocols.
Quantum-Resistant Blockchain: Is immune to attacks from quantum computers. It uses encryption and quantum mechanics to allow two parties to communicate safe data while also detecting and defending against outsiders.
Data Integrity: Is established in blockchain because stored data is immutable and permanent and cannot be changed or erased.
Grover’s Algorithm: Makes it possible to perform quantum searches, allowing users to swiftly identify values among many billions of unstructured data points.
Blockchain Technology: Is a shared, unchangeable ledger that simplifies the process of logging transactions and monitoring assets in a company network.
Cryptocurrency: Is a type of digital currency in which, as opposed to a centralized authority, a decentralized system uses encryption to verify transactions and keep records.
Goppa’s Code: Is a general kind of linear code created by utilizing an algebraic curve X over a finite field, which is an algebraic geometric code.
Advanced Encryption Standard (AES): The United States government selected the symmetric block cipher known as Advanced Encryption Standard (AES) to safeguard sensitive data.
Euclid’s Division Formula: Or lemma can be used to determine the HCF of two numbers. It says that if there are two integers a and b , then q and r must exist such that they satisfy the formula a = bq + r, where O £ r < b .
McEliece Code: Robert McEliece first suggested the McEliece code as a code-based public key cryptosystem in 1978.