(CryptoBriefing) Quantum computers pose a serious threat to most modern cryptography. Cryptocurrency is at risk as well, because Bitcoin and other blockchains rely on encryption at a fundamental level. Here are some of the potential problems – and a few reasons not to worry.
Cryptocurrencies store funds in addresses which rely on encryption. Each public address is controlled by a private key, a secret number that allows you to send your coins elsewhere. Quantum computers have access to advanced algorithms that could deduce private keys extremely quickly. In the future, mainstream cryptocurrencies will probably adopt Lamport signatures, which will provide quantum resistance at the cost of larger block sizes. Ethereum plans to add Lamport signatures in version 2.0 or “Serenity.”
Some altcoins have been working on quantum resistance from the start. Many quantum-resistant algorithms already exist, such as XMSS, Keccack, and Winternitz, which are being applied by projects like QRL, Hcash, and IOTA.
Cryptocurrency is just one small corner of the tech world, and many researchers are working on post-quantum security solutions elsewhere. Practical limitations can also prevent attackers from wreaking havoc on cryptocurrencies. Would-be attackers cannot simply access a quantum computer and carry out an attack: they also need to program those computers to break an encryption scheme, and doing so is not an easy task.