[Cryptography] Some quantum computers might need more power than supercomputers

[Peter Gutmann]

Jon Callas <jon at callas.org> writes:

>Some quantum computers might need more power than supercomputers

The German government (via the BSI) wrote a report on this and estimated that
it would take 100 days and €4M in electricity to recover a single 2048-bit key
on a quantum computer that doesn’t exist.  That's one single key.  There are 7
trillion keys negotiated each year just for TLS web connections.

Oh, and that's for integer factorisation, not (EC)DLP, so not actually useful
for attacking the shopping list of common crypto protocols I mentioned
earlier.

Peter.