John Denker wrote:
[EMAIL PROTECTED] wrote:
From what I understand simple quantum computers can easily brute-force
attack RSA keys or other
types of PK keys.
My understanding is that quantum computers cannot "easily" do anything.
Au contraire, quantum computers can easily perform prime factoring or
perform discrete logarithms - this is Shor's algorithm and has been
known for more than a decade. The difficulty is in making a QC.
Is ECC at risk too? And are we at risk in 10, 20 or 30 years from now?
ECC is also at risk because it relies on the difficulty of discrete
logarithms which are victim to a quantum attack. Are we at risk in 10,
20 or 30 years? Well, as John said, it's hard to say. The first
working 2 qbit computers were demonstrated in 1998, then 3 qbits in the
same year. 7 qbits were demonstrated in 2000. 8 in December 2005. As
you can see, adding a qbit is pretty hard. In order to factor a 1024
bit modulus you'd need a 1024 bit QC. Perhaps if there were some sudden
breakthrough it'd be a danger in a decade - but this is the same as the
risk of a sudden classical breakthrough: low.
My assessment: nothing to worry about for now or in the immediate
future. A key valid for 20 years will face much greater dangers from
expanding classical computer power, weak implementations, social
engineering etc. The "quantum chip" is just a new housing, not anything
that puts RSA or ECC at risk.
Regards,
Michael Cordover
--
http://mine.mjec.net/
---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
