Quantum Computing: What, When, Where, How

This episode explores the intricacies of quantum computing and its implications for blockchain technology, focusing on distinguishing genuine advancements from overstated claims. Against the backdrop of ongoing quantum computing milestone announcements, the discussion clarifies quantum computing's capabilities, noting its potential to break current cryptographic systems used in blockchains and internet commerce. The experts, Dan Boneh and Justin Thaler, explain that while quantum computers excel at specific tasks like finding periods of functions due to constructive and destructive interference patterns, they are not universally faster for all computations. More significantly, the conversation addresses timelines for quantum computing's practical realization, estimating it to be at least 15-20 years away from posing a significant threat to existing cryptography, while also cautioning against premature adoption of post-quantum crypto solutions that may introduce new vulnerabilities. As the discussion pivots to blockchain-specific concerns, it is highlighted that blockchains primarily use signatures rather than encryption, mitigating the risk of "harvest now, decrypt later" attacks, and that blockchains have the capacity to upgrade faster than traditional systems. In closing, the experts advise blockchain builders to prepare for a post-quantum world, but to avoid hasty decisions based on hype, emphasizing the importance of robust security practices and bug prevention in the interim.