Era of quantum computing has began in 1980s when the first useful algorithms were proposed. The most known of them is Shor's algorithm invented in 1994 by Peter Shor. It is designed to quickly factorise large numbers which means finding two numbers which when multiplied together give the original. It may sound like another feature for simple calculator but in fact the most popular and widespread cryptography method RSA is based on the difficulty of factoring large numbers (here created by multiplication of two prime numbers). Breaking RSA 140 (where large number has 140 digits) would take longer than the age of the universe if classical computers would be used. For quantum computer running Shor's algorithm it is a matter of seconds.