
Ask HN: How secure personal information is in Quantum Supremacy world? - gagan2020
Google confirms ‘quantum supremacy’ breakthrough. And, what it means to RSA and other security algorithms that rely on the practical difficulty of factorization. With Quantum Supremacy, these practical difficulties will be gone within month or year. 
What will happen to our personal information saved on various websites? They are becoming more vulnerable.<p>1. Habits, Interest can be hacked easily and we could be targeted and exploited.
2. Financial information like credit card info, bank account info, etc can be scraped off easily, Even from HTTPS (TLS) sites.<p>How ready we are for new world?
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nabla9
You are way off.

Google's new quantum supremacy device has 1,113 single-qubit gates and 430
two-qubit gates.

Consider recent improvement in RSA factorization "How to factor 2048 bit RSA
integers in 8 hours using 20 million noisy qubits"
[https://arxiv.org/abs/1905.09749](https://arxiv.org/abs/1905.09749)

Actual implementation of the device mentioned above requires 2.7 billion
Toffoli gates gates for 2048 bit input and it could factor just one key in 8
hours. Microprocessors reached that high MOS transistor count less than 10
years ago. For example, 8-core Core i7 Haswell-E has 2.6 billion transistors
(2014). If quantum computers follow Moore's law like conventional IC, it will
take 40-years before they can factor 2048 bit RSA.

Symmetric cryptography is already safe against quantum computers. Algorithms
for Post-quantum_cryptography are under development and you might expect to
see them adopted within next 10 years or so.
[https://en.wikipedia.org/wiki/Post-
quantum_cryptography](https://en.wikipedia.org/wiki/Post-quantum_cryptography)

