Secrets, Magic, and Quantum Computing

Dr. Aaron VanDevenderChief ScientistFounders Fund

Any sufficiently advanced technology is indistinguishable from magic.

-Arthur C. Clarke

The Force

Presenter

Presentation Notes

Must save Christmas. Sleigh is powered by the Christmas Spirit.

Presenter

Presentation Notes

Clap if you believe in fairies

Magic is powered by belief

Cryptography is Literally Magic

RSA Public Key Cryptography• Rivest, Shamir, Adelman invented in

1977• Uses a one-way function• Based on un-proven mathematical

conjecture that large numbers are hard to factor into their primes.

• Used for secrecy, signing, authentication, irrefutability

Belief Security

Secrets

Trust

Alice, Bob, & Eve

Digital Signatures

• Software updates• Website spoofing• Email authentication

Shor’s Algorithm

• First useful quantum algorithm (1994)• Turns factoring into a periodicity problem• Polynomial time• Will be the last to be implemented

Quantum mechanics is the cause of—and solution to—all life’s problems.

Quantum Key Distribution

• Charles Bennett, Gilles Brassard, Artur Ekert, et al.• Great for secrecy• Bad for trust• Not magic

Quantum mechanics limits what is knowable

• Heisenberg uncertainty principle• Cannot measure position and momentum at the same time• The universe keeps secrets

No cloning theorem• Quantum states cannot be copied• Attempting to measure alters the state• WPA2 KRACK

Public Key Infrastructure

• Web of Trust• State distribution contrary to no-cloning• State estimation

Reversible Computation

• Irreversible computation embeddable in reversible

• Quantum computation superset of classical

• Energy loss during erasure• Time reversal symmetry

Rubik’s Cube

• Reversible• Linear transformations • Operations are rotations• Don’t create or destroy information

• Require irreversibility• One-way functions• Hash functions• Fully avalanched

Cryptography Primitives

BitCoin• SHA-256 vulnerable to Grover’s algorithm• Only quadratic• Signed transactions are vulnerable• New network design

Quantum Money

• Stephen Weisner, Scott Aaronson, Paul Christiano, Andrew Lutomirski, et al.

Post-quantum cryptography• Lattice codes• Error correcting codes• Multivariate codes• Magic! (but maybe stronger magic)

Gödel’s Incompleteness Theorem

The only way of discovering the limits of the possible is to venture a little way past them into the impossible.

-Arthur C. Clarke

Thank you!