Cardano (ADA) has been ranked second on a list of blockchains that has the potential to resist any future quantum-computer attacks. In a paper from Google Quantum AI shared by Cardano representative dori, she notes that the ranking was based on how prepared blockchains were to upgrade to “post-quantum cryptography.”
Cardano secures second place as Algorand leads
Notably, the ranking considered blockchains based on whether public keys were exposed and if the protocol supports key rotation or upgrades. It also factored in how long transactions stay vulnerable before they are confirmed on the blockchain.
As per the ranking, Algorand is the only blockchain ahead of Cardano because it has already tested quantum-resistant transactions in a live environment and supports rotating keys. This implies that if quantum threats were to surface now, only Algorand, theoretically, has the infrastructure to migrate its users to safer cryptography.
Cardano, for its part, is considered safe by design, as it hides public keys longer than other blockchains. Cardano uses the eUTXO model, where spending keys remain hashed until funds are spent. This design confers a level of protection on users in the ecosystem.
The feature prevents any potential attacker from seeing the key until the transaction occurs. Other projects on this level with Cardano include Dogecoin, Zcash and Bitcoin Cash. All of them have been termed “tier 2” by the Google Quantum AI paper. That is, they are structurally at an advantage compared to other blockchains.
Meanwhile, the paper has two other categories of blockchain, described as “vulnerable but preparing” and “broadest attack surface.” XRP Ledger, Litecoin and Bitcoin fall into the “vulnerable but preparing” category.
The networks of these blockchains generally expose public keys more often, which potentially leaves them open to quantum attackers.
Ethereum and Solana are considered to have the broadest attack surface because their public keys are always visible. This flaw offers quantum attackers high opportunities to strike.
Cardano’s preparedness for post-quantum security
It is worth mentioning that the research paper is interpreting blockchains based on future projections, as quantum computers that can break the cryptography of networks that do not exist yet. They remain a future possibility, which some analysts consider is over 10 years away.
Additionally, most blockchains are already planning upgrades via forks before the threat happens. For instance, the Ethereum Foundation says it is actively planning a quantum-safe migration around 2029.
Interestingly, Cardano Midnight’s Chief Technology Officer, Sebastian Guillemot, in October 2025, assured users that the platform is safe from quantum computer threats. This signals that the Cardano blockchain has been proactively preparing ahead of future potential threats.
Source: https://u.today/cardano-named-second-most-quantum-ready-blockchain-by-google
