Quantum security is a branch of cryptography that is focused on the development of cryptographic algorithms that are resistant to potential attack from quantum computers. The aim is to protect confidential information against adversaries who have access to a powerful quantum computer in order to break existing public key cryptography systems. Quantum security uses laws of quantum physics to protect sensitive information and communication, such as quantum key distribution and quantum encryption.

**What is Cryptography?**

Cryptography is the practice of using complex mathematical algorithms and codes to protect sensitive information or data by making it unreadable to anyone who isn’t authorized to see it. Cryptography is important because it helps protect sensitive data from hackers. It also helps to ensure that only authorized users can access certain information.

Cryptography is used to verify the identities of users and to encrypt communications, making it harder for third parties to observe or intercept messages. Additionally, cryptography makes digital signatures possible, which helps add an extra layer of security and trust to online transactions. It is used to protect digital communications, improve data security, and securely store data. Cryptography is used in a wide range of applications, such as online banking, email encryption, and secure file sharing.

The earliest known use of cryptography was found in hieroglyphic inscriptions on the tomb of Khnumhotep II, an Egyptian nobleman who died around 1900 BC. Hieroglyphics used cryptography by providing a method of writing which obscured the meaning of words and messages from those who lacked the knowledge to decipher it. This type of encryption made it possible for ancient Egyptian scholars and priests to keep sacred texts and secrets safe from those who wanted to access or learn from them. By using symbols or pictographs instead of actual written words, hieroglyphics provided an effective form of encryption that was extremely difficult to crack.

Data is typically secured using these Encryption types:

**Symmetric Encryption**(also known as Secret Key Encryption) is a type of encryption involving the use of a single key that is shared between two parties to encrypt and decrypt data. Examples are — Advanced Encryption Standard (AES), Data Encryption Standard (DES), Skipjack, Twofish, Blowfish, Rivest Cipher 4 (RC4), International Data Encryption Algorithm (IDEA), and Diffie-Hellman key exchange algorithm.**Asymmetric Encryption**(also known as Public Key Encryption) is a type of encryption involving the use of two different keys — a public key and a private key, which are used to encrypt and decrypt data. Examples are — RSA (Rivest–Shamir–Adleman), Diffie-Hellman Key Exchange, Elliptic Curve Cryptography (ECC), Digital Signature Algorithm (DSA), and ElGamal encryption.**Hashing**is not a form of encryption, but rather a one-way transformation of plain text into an unreadable string of characters. The earliest known use of hash functions dates back to the early 1950s when Professor Hans Peter Luhn invented the one-way hash function. It was initially used as a tool for fraud prevention.**Digital signatures**are used to verify the authenticity of a message or a digital document by using a combination of public key and private key encryption.**Steganography**is a form of security through obscurity that hides data within other types of digital media such as images or audio files in order to protect it from unauthorized access. In 440 BC, Histiaeus of Miletus inscribed a message on the scalp of a slave and shaved off the hair so that the message would be hidden until the slave’s hair grew back.

**Quantum Communication**

Quantum communication is a form of communication that uses quantum mechanical phenomena, such as entanglement and quantum teleportation, to securely transfer information over a distance. Quantum communication systems have the potential to revolutionize communication and secure data exchange in the future. Quantum communications will rely on encryption algorithms and cryptography in order to keep data secure.

Quantum encryption algorithms are used to secure communications by encrypting data, while quantum cryptography is used to verify the validity of the data being exchanged, ensuring that it is coming from the intended sender. Both of these technologies rely on principles from quantum mechanics, such as entanglement and superposition, which make them more secure than traditional encryption methods.

**How is data secured with the latest Quantum Encryption algorithms?**

This type of encryption is used to create secure keys that cannot be broken by any existing classical computing system. Generally, quantum encryption algorithms rely on the Heisenberg Uncertainty Principle, which states that it is impossible to measure certain properties of a particle at the same time. This property can be used to generate a key that can only be unlocked by possessing two pieces of information at the same time, thus making it impossible for an attacker to unlock the data without knowledge of both pieces.

- BB84 Quantum Key Distribution, which was developed by Charles Bennett and Gilles Brassard, is an algorithm that is used for the secure exchange of cryptographic keys over a quantum channel.
- Ekert Quantum Key Distribution Protocol, also known as E91 Protocol, is an algorithm that was proposed by physicist Artur Ekert in 1991 and can be used for secure key exchange over quantum channels.
- Quantum Steganography, which was developed by Rosalind Y. Bignell and her colleagues, is a protocol that uses quantum entanglement to hide encrypted information within a physical system such that only the sender and receiver have knowledge of its presence.
- Quantum Hashing is an algorithm that uses a special type of mathematical function known as a hash to generate a unique encryption key for each individual data transfer. It is based on the principle of quantum entanglement and provides secure authentication and data integrity. Quantum entanglement in this case is the process by which two or more particles are linked in such a way that the quantum state of each particle cannot be described independently of the others, even when separated by a large distance. This phenomenon is described in quantum mechanics and enables the transmission of information faster than light.
- Quantum Encryption with Unconditional Security is another algorithm. It was developed by Hoi-Kwong Lo and his colleagues, and provides unconditional security over a quantum channel and is therefore considered the most secure encryption system available.
- CRYSTALS-Dilithium, FALCON, and SPHINCS are three post-quantum cryptography algorithms that are being developed as part of the National Institute of Standards and Technology’s (NIST) Post-Quantum Cryptography Standardization process. CRYSTALS-Dilithium is a lattice-based cryptographic algorithm, FALCON is a hash-based signature algorithm, and SPHINCS is a hash-based signature scheme.

**What is Quantum Cryptography?**

Quantum cryptography works by employing the laws of quantum mechanics to encode data. A secret key is randomly generated by the sender and placed into a quantum state, such as a single photon. This single photon is then sent to the receiver. If the transmission is intercepted, the attacker will disturb the quantum state of the single photon, or the photon will be lost due to the no-cloning theorem, thus alerting the receiver of a potential breach. Once the single photon reaches its destination, the sender and receiver can use the key to securely encrypt any data they exchange afterwards.

Quantum cryptography is inherently secure and resistant to tampering, eavesdropping, and other forms of attack. The foundations of quantum cryptography are based on quantum physics and the principles of entanglement and superposition. This means that even single photons can be used to send encrypted messages between two locations. Quantum key distribution can be used to securely exchange information with high-level encryption that cannot be broken by classical computing methods. Quantum cryptography is being used for various communication applications such as financial transactions and database access. There are four types of Quantum cryptography.

**Quantum Key Distribution (QKD)**

QKD is a type of cryptography that uses the principles of quantum mechanics to securely exchange a cryptographic key between two distant parties. In a typical QKD system, two parties, Alice and Bob, are connected by a communication channel and share an entangled pair of particles. Alice encodes a secret message by manipulating the particles, usually through polarization. Bob receives the particles and attempts to measure their properties in order to decode the secret message. If an eavesdropper, Eve, attempts to intercept the message, the entanglement of the particles is disturbed, alerting Alice and Bob that their communication has been compromised. This process ensures secure communication of encryption keys between Alice and Bob.

Quantum-secured communication protocols exist to allow for secure access to the internet. These protocols use quantum key distribution (QKD) in order to securely encrypt data as it is transmitted over the internet. The encryption provided by QKD is much more robust than traditional methods of encryption, making it much harder for attackers to intercept and decrypt the data.

**Continuous Variable Cryptography (CVQC)**

CVQC is a type of cryptography that uses continuous variables such as the quadrature components of a single-mode light beam (these are two separate components or beams that have a relative phase difference of 90 degrees. These two beams are orthogonal to each other and are referred to as the horizontal and vertical components of the beam. The beams can be used to measure the phase of the original beam as well as to carry out interferometric measurements) to create a secure channel.

The main benefit of using an interferometer for data transmission is that it offers an extremely reliable and efficient way to send and receive large amounts of data. Interferometers transmit data using light waves, which can travel much farther than traditional electronic signals and can be very accurately focused. This allows for high-speed data transfer over longer distances than would otherwise be possible. Additionally, interferometers are highly resistant to interference, providing a reliable and secure connection.

CVQC is an emerging quantum cryptography technique that leverages the properties of continuous-variable quantum systems to achieve greater levels of security than previously possible. In classical cryptography, the security of data transmissions is based on the difficulty of breaking the encoding schemes used to protect it. In CVQC, however, encryption and decryption are achieved using only quantum mechanical phenomena, making it virtually unbreakable. This makes CVQC especially attractive in cases where the need for secure information transmission is paramount, such as in banking and military communications. Unlike traditional cryptography, CVQC ensures that transmitted data remains secured even if intercepted or compromised by a third party.

**Quantum Signature Schemes**

Quantum signature schemes are a type of cryptography that allows two parties to authenticate each other and also to prove the authenticity of any messages they exchange. Quantum signature schemes are cryptographic protocols that use quantum mechanics to secure digital signatures. These types of schemes typically involve a two-party system, where one party wants to prove the identity of the other and vice versa. They rely on quantum key exchange methods, such as entanglement, to establish secure communication between the two parties and validate each other’s identity. Quantum signature schemes are secure against both classical and quantum attacks, making them very robust against potential attackers.

**Quantum Random Number Generation (QRNG)**

QRNG is a type of cryptography that uses quantum mechanics to generate a sequence of truly random numbers that cannot be predicted by classical methods. Quantum Random Number Generation (QRNG) is an advanced technology that utilizes physical phenomena from the quantum world to generate sequences of random numbers. It is based on the principles of quantum mechanics, which govern how particles behave at the subatomic level. By exploiting uncertainties inherent in these behaviors, QRNG can provide more randomness than traditional sources like pseudo-random number generators and mechanical or electronic noise. This enables applications with higher security requirements, such as cryptography, security protocols and secure communications.

It is clear that the potential of quantum cryptography has yet to be fully realized, but with continued research and development it could provide a secure and efficient means of communication for the future.

In conclusion, it is clear that quantum cryptography holds significant potential for secure, efficient communication across a variety of channels. With further research and development, this advanced technology could revolutionize digital communication in years to come.