GoogleCTF 2019 - Quantum Key Distribution (Crypto, 90)


Generate a key using Quantum Key Distribution (QKD) algorithm and decrypt the flag.

webpage : challenge

This challenge needs us to do Quantum key distribution (BB84) with server.

BB84 has two basis : x and +

we must send our basis and qubits to server.

server will send their basis back to make the shared key.

Then this key can decrypt the flag well.