KEYWORDS

• Quantum computer
• Cryptographic security

INTRODUCTION

Explain before introducing the news...

• Moore's Law is said to be the limit　(High integration)
  
• In the future, a new breakthrough is necessary
  • Quantum computer
• Expected quantum computer to be active in various fields
  • Machine learning
  • Optimization problem

quantum computer

• Instead of the logic gate, performing quantum computation using quantum gate
• Use Quantum bits
• Quantum bits can take both "0" and "1" states with the same probability
  • At the same timing

Break RSA encryption?

• RSA core concept: Huge number of prime factorization is difficult with classical computers
  • Public-key cryptograph
    
• Even though the multiplication of prime numbers is EASY!(hard for humans...)
• It takes a huge time for prime factorization of a huge number
• But...There is an algorithm that can solve prime factorization in polynomial time
  • Polynomial time $O(n^c)$ <<<<< Exponential time $O(c^n)$
• Will it break if it is a quantum computer?
  • The answer? is in the following article

NEWS

• The world's first quantum computer in international conference

https://www3.nhk.or.jp/news/web_tokushu/2017_0627.html

• RSA & quantum
  • http://gigazine.net/news/20170522-why-quantum-computers-might-not-break-cryptography/