As blockchains become ever more popular and widespread, a growing concern is their sustainability. Current designs, most notably the blockchain underlying the Bitcoin cryptocurrency, are secured using so-called “proofs of work,” which requires huge amounts of computational power. This is an ecological problem challenging the long-term viability of cryptocurrencies. In an ongoing collaboration, Institute of Science and Technology Austria (IST Austria) Professor Krzysztof Pietrzak and BitTorrent inventor/Chia Network CEO Bram Cohen seek to address this problem by making use of disk space rather than computational work. Research into one of the two key components of this approach—”proofs of sequential work,” also known as “verifiable delay algorithms,” received this year’s Best Paper Award at EUROCRYPT, one of the world’s top two cryptography conferences.