SESSION ID: ACB-W02 Understanding and Explaining PostQuantum Crypto with Cartoons Klaus Schmeh Consultant cryptovision @cryptovision #RSAC Please welcome ... A quantum computer! Hello! Quantum computer Based on quantum mechanics Schrödinger‘s cat Quantum bit Dead and alive at the same time 0 and 1 at the same time What are you good at? Extremely many computations in parallel, if there is only one result Examples: • Find element in large set • Find optimal solution What are you not good at? Sorting. Because sorting has more than one result. What are you especially good at? Prime factorization! Prime multiplication Prime factorization 17⋅23 = ? 377 = ?⋅? simple difficult Prime multiplication is a one-way- function RSA is based on prime multiplication 17⋅23 = 391 Alice‘s private key Alice‘s public key In practice, prime numbers have ~2048 bits I can break RSA within seconds. Up to a key length of 5 bit. Future versions will be more powerful. Thank you for coming! Klaus Schmeh, Chief Editor Marketing at cryptovision. My books A quantum computer can break RSA and other crypto systems! We need to look at alternatives! Six families of crypto algorithms are considered quantum-proof. code-based hash-based non-commutative multivariate isogeny-based lattice-based None of these is in wide-spread use. We are going to look at three of them in detail. Please welcome … Mr. Snail! Can you explain latticebased crypto to us? I even can explain lettucebased crypto. Lattice-based Lettuce field: known as lattice in mathematics. Lettuce field Lettuces (lattice points)