[ExI] You'd better sell your bitcoins

[Jason Resch]

On Wed, Nov 19, 2025, 5:08 PM Keith Henson via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> I don't know how the SWIFT network is secured.  Long ago, it was DES,
> but John Gilmore built a cracking machine and showed how easy it was
> to brute force crack.  I think they went to triple DES which is 56 x 3
> bits.  If quantum computers can crack the SWIFT network (I don't
> know), I think that would be a much larger problem than Bitcoin.
>
> Anyone know?
>

The problem is less in the symmetric cipher's like DES (and now AES) and
moreso in the key exchange and digital signature algorithms which are
primarily RSA, Elliptic Curve and Diffie-Hellman. (You may enjoy my
presentation if you are interested to understand how these algorithms work
and what they are used for: https://youtu.be/mSMQ-xowqAg )

These three algorithms are instrumental to all transport security protocols
(SSL, TLS, SSH) which are the basis of HTTPS, SFTP, VPNs, etc.

Due to the fact that all these constructions are based around mathematical
groups they all fall to Shor's algorithm and quantum computers. But this is
a particular quirk of history, the simplest asymmetric encryption
algorithms were based on mathematical groups, and were invented in the 60s
and 70s, but they don't have to be. New constructions, for example, based
on lattices were invented in the 90s and don't use groups and hence are not
vulnerable to Shor's algorithm.

So you are right this affects much more than cryptocurrency. Practically
all secure communications protocols on the Internet are vulnerable. More
worrisome: of someone, such as a hacker or government actor recorded any
communication based on these protocols, once a large scale quantum computer
is created, all these historical messages can be exposed.

If you have a credit card with an expiry date that is after a large scale
quantum computer is invented, and it was used in the past over a secure
connection that was recorded, then it can be determined determined in the
future just as a cryptocurrency wallet could be exposed by a quantum
computer.

There are already browsers and servers using new TLS standards and
cryptographic protocols that incorporate post-quantum-secure algorithms
into the key exchange and/or digital signatures. Signal and iMessage
reportedly already use it:

https://blog.cloudflare.com/pq-2024/

Jason



>
> On Wed, Nov 19, 2025 at 5:27 AM Adrian Tymes via extropy-chat
> <extropy-chat at lists.extropy.org> wrote:
> >
> > On Wed, Nov 19, 2025 at 8:15 AM John Clark <johnkclark at gmail.com> wrote:
> > > On Tue, Nov 18, 2025 at 10:49 AM Adrian Tymes via extropy-chat <
> extropy-chat at lists.extropy.org> wrote:
> > >>> >> Nobody can pinpoint the exact day a quantum computer capable of
> running Shor’s algorithm will become operational,
> > >>
> > >> > And I am not.  The sequence of events is:
> > >> * That computer comes out.
> > >> * Sell your Bitcoins at this point.
> > >
> > > And at that point the price of bitcoin would have already dropped by
> at least 95%, probably more.
> >
> > No panic before this point, therefore, no 95% drop.
> >
> > >> > * The public demo of the algorithm is run.
> > >> * Then there might be a panic.
> > \>
> > > Might?!
> >
> > Might,
> >
> > >> > The panic won't happen until the public demo of the algorithm,
> > >
> > > The panic will happen as soon as the smart money realizes that such a
> demonstration is imminent, so for your strategy to work you would need to
> be smarter than the smart money. Are you that smart?
> >
> > The smart money itself won't initiate the panic, by definition.
> > That's a small percentage of the investors.
> >
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