Sustainability of Public Key Cryptosystem in Quantum Computing Paradigm

Introduction

Today is an era where a smart phone provides anytime anywhere services and stores personal data, including photos, messages, mails and documents. Instead of files and folders people use icloud, Microsoft one drive, Google cloud as backups. From small start-ups to Microsoft, Google, IBM, AT&T, Amazon store their data in data-centres and cloud. With the emergence of technological revolution to host services over internet, it has resulted in exponential growth of data stored in data-centres and cloud. Storing data in data-centres and cloud entails securing data from thieves, who secede valuable or sensitive data from storage centers and eavesdroppers, who listen or capture data on the communication channel while it travels from provider to user over World Wide Web. Hence secure communication of this data becomes critical.

Cryptography is the collection of techniques to communicate data only to its intended user in presence of third parties. These techniques suggest that before the data enters the communication channel, hide the data using encryption techniques and then on reaching its destination unhide the data using decryption techniques. Hence cryptographic protocols are being in practice to secure the data transmission over network.

Traditionally cryptographic protocols involve use of a secret key, which is agreed upon by the sender and the receiver over a secure channel, to encrypt and decrypt this data. Ramification of this protocol is key distribution problem. To eliminate the use of a single key Diffie and Hellman devised a solution based on the concept given by Merkle(Merkle,1978). Merkle suggestion was to communicate the message over insecure channel by creating a puzzle and encrypting some information in the puzzle such that it requires exponentially more efforts from eavesdropper to solve the puzzle than the receiver.

Since the advent of quantum computing paradigm in 1980’s, Richard Feynman and David Duetsch envisioned the massive computing power of quantum systems. Quantum computation provides parallelism because of phenomenal characteristics of quantum physics like superposition and entanglement to perform operations on data. Shor(1994) proposed a quantum algorithm that has severe implication on current classical algorithms for public key cryptography. The traditional cryptosystems are challenged to sustain and provide adequate security. So there is need to replace the existing cryptosystem with new protocols, resistant against the attacks due to quantum computing power. The only solution with us is to either switch to quantum cryptography algorithms or to reformulate the classical cryptosystem resistant to quantum paradigm.