1. Possible Impact of quantum computing
Facing new technologies:
Presented by
Olga Surzhok
Justin Matte

2. Quantum computer vs. classic computer
Bit and q-bits
Classic bits correspond to a collection of physical systems, each of which can exist in two unambiguously distinguishable physical states, associated with the value (0 or 1)
Quantum bits or “qbits” do not have the limitation of two states and can be in any superposition of 2n classic states of (0, 1).
Superposition
Superposition principle states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually
Example: Schrodinger’s Cat

3. Cryptography and post-quantum cryptography
Public-private key encryption
Focuses on having two mathematically and uniquely related keys
Relies on the computational-intensive complexity of mathematical problems that are easy to compute in one direction, but hard to compute in the other direction
Ability to find the private key to associated public keys is limited and highly time consuming
What’s the problem when quantum computer is brought into the equation?

4. Post-quantum cryptography
Hashing functions
Given a hash function h that produces a hash of length n, a standard birthday attack which works against any hash function can find a collision in 2n/2 time
This problem is solved by choosing an n that is >= 256
Generic quantum attack that is more efficient and takes 2n/3 time
Solution? Choosing n to >= 384, h becomes collision resistant even to quantum computer attacks

5. Advantages, disadvantages and ethical implications
Several issues:
Monopolization of quantum computing
Pros and cons for scientific computing
Privacy vs. security
How to make the impact positive

6. Questions?