Story perspectives

Google Warns: Quantum Computers Could Threaten Bitcoin Security

3/31/2026

Summary

Story summary

Google researchers warn future quantum computers could break Bitcoin and Ethereum cryptography with under 500,000 physical qubits.
The finding reduces earlier estimates and raises security concerns for blockchain transactions, including Bitcoin's 2021 Taproot upgrade exposing public keys.
Google has set a 2029 deadline for migrating to post-quantum cryptography.
Experts say the crypto industry must act quickly to mitigate risks as the threat timeline tightens.

History

Historical Context

In 2019, Google announced it achieved quantum supremacy with its Sycamore processor, completing a task in 200 seconds that would take classical computers 10,000 years. This breakthrough raised concerns for cryptographic systems like Bitcoin and Ethereum, as quantum computers could undermine traditional encryption methods. Experts warn that under 500,000 qubits could threaten blockchain security, prompting the crypto industry to seek post-quantum cryptography solutions by 2029.

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Story summary

Google researchers warn future quantum computers could break Bitcoin and Ethereum cryptography with under 500,000 physical qubits.
The finding reduces earlier estimates and raises security concerns for blockchain transactions, including Bitcoin's 2021 Taproot upgrade exposing public keys.
Google has set a 2029 deadline for migrating to post-quantum cryptography.
Experts say the crypto industry must act quickly to mitigate risks as the threat timeline tightens.

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