The National Institute of Standards and Technology (NIST) has put forward a proposal to standardize an expanded variant of the Advanced Encryption Standard (AES), augmenting its block and key size to 256 bits. NIST is currently seeking public feedback on these proposed modifications until June 25, 2025. The initiative to increase the block size stems from the necessity to accommodate applications processing larger volumes of data and the rising demand for these data-intensive solutions.
Currently, AES utilizes a block size of 128 bits with varying encryption key lengths—128, 192, or 256 bits. By extending encryption key lengths, the cryptographic framework can achieve improved security against quantum computing threats. This is essential, as long as the encryption key lengths surpass the bit size quantum computers can effectively factor and compromise, thereby ensuring the system’s cryptographic security remains intact.
The emergence of quantum computers poses challenges to existing encryption standards, impacting sectors such as banking, cryptocurrencies, and military intelligence. This concern has been accentuated following Google’s disclosure of its Willow quantum processor, which claims the capability to solve problems in five minutes that would take traditional binary-based computers 10 septillion years to solve.
Despite the impressive computational advancements, quantum computers still grapple with inherent design constraints, such as qubit allocation for error correction, which safeguard existing encryption standards from being easily broken. To safeguard against the advent of quantum supremacy, Ethereum co-founder Vitalik Buterin has unveiled a strategy to quantum-proof Ethereum through account abstraction as part of the network’s roadmap. He has emphasized that, while preparations for quantum computing advances are necessary, it may be decades before quantum machines pose significant encryption risks.
Various organizations are already experimenting with post-quantum cryptography solutions. For instance, the Singapore Monetary Authority and Banque de France have recently completed tests applying post-quantum security to Microsoft Outlook email communications. Moreover, hash-based quantum-resistant solutions have been proposed for securing systems that rely on elliptical curve digital signature algorithms.
Nevertheless, Adam Back, co-founder and CEO of Blockstream, has expressed skepticism regarding the immediate practical application of hash-based schemes. He suggests that these methods may not be adopted widely in the near term but anticipates that research into quantum-resilient solutions will continue to advance in anticipation of future quantum computing breakthroughs.
