Google moved up its quantum computing threat deadline to 2029, meaning powerful quantum computers could decrypt years of captured encrypted messages within 33 months if platforms don't switch to quantum-resistant algorithms before then. The 'store-now-decrypt-later' attack is already a concern today — adversaries are capturing encrypted traffic now, banking on being able to decrypt it once quantum computers arrive. Most major platforms have already started the transition to post-quantum cryptography (NIST finalized the standards in 2024), but older messaging apps and some cloud services still need urgent updates, particularly for key agreement systems and authentication.