Exposing the keys
The crypto industry relies on blockchain technology, a shared and transparent digital ledger that records transactions across decentralised networks.
They are secured by mathematical security systems to create public and private digital keys, which act like account numbers and secret passwords to verify ownership and authorise transactions.
Public keys become visible to everyone whenever crypto is transferred. While regular computers cannot use a public key to figure out a secret private key, powerful quantum computers could do so easily.
This capability would allow cybercriminals to forge digital signatures and steal funds. The threat is severe because blockchain transactions are permanent and cannot be reversed like traditional bank payments.
Bitcoin, which is the most popular cryptocurrency, is highly vulnerable as its 17-year history has left millions of public keys exposed.
Research from 2025 estimates this vulnerability could affect up to 50% of the network. If a hacker successfully steals and dumps a massive amount of tokens, market prices could crash entirely.
Upgrading the networks
Despite the rising concerns, many experts believe it will take a few years before quantum computers can successfully crack blockchain security, giving the industry time to upgrade to new, quantum-resistant security systems.
However, executives warn that upgrading too early brings its own risks because the new technology is changing rapidly.
Quantum-resistant digital signatures require far more data storage and bandwidth. These heavier data requirements could slow networks down and raise transaction costs, a major issue for blockchains with rigid capacity limits, like Bitcoin.