A Group of Seven (G7) cybersecurity working group urged governments and companies to immediately begin shifting to post-quantum cryptography. While the arrival of practically usable quantum computers is uncertain, it judged that technology capable of threatening existing public-key cryptography is advancing faster than expected. Cryptocurrency networks are also facing quantum computing as a new security challenge because they use public-key cryptography for transaction signatures and fund management. On Sept. 5 local time, blockchain outlet Cryptopolitan reported that the G7 cybersecurity working group released a report on Sept. 3 titled "Preparing for the Post-Quantum Era: A Call to Action". The report stressed that governments and companies should begin the transition to post-quantum cryptography before quantum computers can actually neutralise existing cryptographic systems. The G7 did not present a specific timeline for when quantum computers will be commercialised. It said recent technical advances point to the likely development of quantum computers capable of breaking widely used public-key cryptography. In particular, the G7 identified "harvest now, decrypt later" attacks as a key risk. In such attacks, an attacker secures encrypted data now and decrypts it later when quantum computers become sufficiently advanced. The blockchain industry is also paying attention to such risks. Because blockchains are structured so transaction records and some public-key information remain for long periods, there are concerns that even currently secure cryptography could become a target of future attacks using quantum computers. The G7 recommended that countries pursue not only new cryptographic algorithms but also national-level policy, research, public-private cooperation and procurement standards that take post-quantum technology into account. The European Union has already presented a specific transition schedule. In June last year, the EU introduced a joint implementation roadmap for the shift to post-quantum cryptography and told member states to begin the transition by the end of 2026. It