As of 2026-03-02, the state of the art in quantum decryption has cracked a:
- 22-bit RSA key
- 6-bit elliptic curve key
https://forklog.com/en/quantum-computer-cracks-tiny-cryptographic-key
The IBM QC that cracked the 6-bit key uses 133 qubits.
Some new research suggests that RSA-2048 could be cracked with as "few" as 100,000 qubits.
Such a machine...is not feasible to build any time soon.
So when your CISO or a vendor starts going off about "post-quantum" security, feel free to use this to remind them that we still have SMB1 in some places and Telnet in others. Plenty of work to do around the house.
