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Quantum

and Post-Quantum CryptographyRecent years have prompted research into quantum computers.

Quantum computers have been the subject of controversy due to their abilities

to solve complex mathematical phenomena that have been primarily developed as

the basis of information encryption. Given that these large quantum computers

are built, they shall inevitably compromise the key cryptosystem that is

currently in use. This would jeopardize the confidentiality presently enjoyed

by digital communication and internet users worldwide. The primary objective of

post-quantum cryptography is to create cryptographic systems that can

interoperate with existing communication protocols. This paper shall look into

common cryptographic topics and reflect the effect of post cryptographic

quantum computing on common information encryption. Quantum key distribution Quantum key distribution is indeed a successful application

to cryptography, quantum information that utilizes the quantum mechanics theory

to secure data (Quantum.ukzn.ac.za.). Quantum key distribution generates a

random key between two points over an insecure network. Quantum key

distribution is founded the superposition principle and the Heisenberg’s

principle. A one- time pad encryption

scheme is created and implemented using the securely distributed quantum

key. A great protocol of quantum key

distribution is the “BB84” protocol in which single qubits are chosen

randomly from {???, ???, ???, ???} states and sent. For QKD

the key used for encryption should only be used once. This removes the chances

of prediction from an eavesdropper or from the sender/receiver. Hence Quantum

key distribution guarantees integrity over an insecure channel unlike in

post-quantum cryptography whose key algorithms’ security rely on tough

mathematical problems and the capability of a quantum computer, one that ideally

runs Shor’s algorithm, to solve them these problems. Symmetric cryptography & Symmetric key management

systems and protocols Cryptography

involves the process of making messages non-readable by encypting them with

different algorithms. Cryptographic algorithms are grouped into two types of

encryption: symmetric and asymmetric encryption.In Symmetric encryption a

single key is used for the encryption and decryption proccess. A crucial problem that lies in

symmetric key cryptography is the distribution of the secret key. The key

distribution must happen secretly. However key sharing can happen in one some

ways; a trusted third party could get involved in sharing the key with the

recipient. Alternatively, the sender can physically deliver the key to the

receiver. If the sender and receiver have previously used a key, they can

communicate the new key through encryption using the old key. Nonetheless this

option of distribution is hazardous because of the fact that an eavesdropper

can gain access to the old key and acquire the new key by intercepting

communication of the new key

Hash functionsA cryptographic hash function receives

a message as input and produces what is known as a message digest of

predetermined fixed length. One property of a cryptographic hash function is

that the digest from the hash function for any given message is impossible to

compute for those with a given hash. Another property of the cryptographic functions

have is uniqueness There are collisions of hash functions put the probability

is low 1?e/(?k(k?1)/2N). However with the development of quantum computers, it

is very likely that using the hash value, the initial message could be computed

and derived successfully. This would in a high magnitude compromise the

integrity of information passed over an insecure channel. Other practical

applications that use hash functions such as digital signatures and

authentication also face an integrity threat following the development

post-quantum cryptography.

Public key cryptography Public key cryptography also known

as asymmetric encryption uses two non-identical for communication. The two keys

involved are a public and a public key. Each of these two keys have different roles;

the public key encrypts the message while the private key decrypts the message.

Private keys can however not be computed from public keys. Public keys are

therefore shared hence allowing users a convenient content encryption platform.

Given that the public keys have to be shared for decryption and encryption to

take place , they are therefore stored within digital certificates to

facilitate structured and secure sharing among communicators. Users, therefore,

have them at their disposal for encryption during information sharing. However,

only the users of private keys can decrypt the information.

Shor’s algorithm

Shor’s

algorithm was developed by a mathematician known as Peter Shor. His innovation

brought about a quantum algorithm for integer factorization. All it takes is one post cryptography quantum

machine with enough qubits to solve quantum gates for 0((log N) 2(log log N) (log log log N)). For this

reason, therefore, these quantum computers can break public key cryptography

which is based on Shor’s algorithm. The

public key encryption is pegged on a principle huge numbers are computationally

impractical. This phenomenon is however

only valid for classic computers. The development of quantum computers

withstanding, software developers need to reach common ground with mechatronic

engineers in developing computing systems that shall not compromise the

integrity of information reliance and computing.