In short
- Tezos launched TzEL, a post-quantum privacy system for blockchain payments on testnet.
- Arthur Breitman accused parts of the Bitcoin community of dismissing legitimate quantum risks.
- The project aims to protect encrypted blockchain transaction data from future decryption attacks.
Although practical quantum computers that can break modern cryptography do not yet exist, Tezos co-founder Arthur Breitman said some parts of the crypto industry are treating quantum computers as a conspiracy theory while ignoring a legitimate threat to blockchain privacy.
The warning comes as Tezos launches TzEL, a post-quantum privacy system on testnet designed to protect private payments and encrypted transaction data from future ‘harvest now, decrypt later’ attacks. Breitman said Tezos is acting with “a sense of urgency,” while he said parts of the industry remain complacent about quantum threats.
“Some projects are barely maintained and will not be upgraded at all; but the important projects will be upgraded, usually on time,” Breitman told us. Declutter.
Breitman was particularly concerned about some in the Bitcoin community who were promoting what he described as pseudoscientific theories about quantum computers.
“There are Bitcoiners being applauded on stages for half-baked theories of quantum mechanics that contradict established physics,” he said.
The cultural debate centers on whether blockchain networks should now start preparing for a future in which quantum computers could break the elliptic curve cryptography that is widely used in cryptocurrencies today.
The concern is especially acute because blockchain data is permanent. By design, transactions and other data are publicly stored on-chain indefinitely, creating the opportunity for what security researchers call a “harvest now, decrypt later” attack.
In such a scenario, attackers collect blockchain data in the form of public keys and store it until quantum computers become powerful enough to break the cryptography that protects them, exposing private keys and stealing funds.
However, one challenge for post-quantum privacy systems is scale. Quantum-resistant zk-STARK proofs are significantly larger than the proofs used in many existing blockchain privacy tools, creating storage and throughput issues. Breitman said Tezos is equipped to meet that challenge.
“Post-quantum shielded transactions can take up a lot of space,” he said. “Tezos has a functioning data availability layer that can absorb it without increasing the load on consensus nodes.”
The project remains experimental and, according to Breitman, several steps still need to be taken before it can be deployed on a broader scale. He added that Tezos has also begun introducing post-quantum signature support for user accounts as part of a broader effort to prepare the network for future threats.
“The fact that the encrypted memo can be decrypted in the future means there is value in switching early,” Breitman said. “The work to make the entirety of Tezos post-quantum is active and ongoing.”
Breitman argued that the industry still has time to prepare for quantum threats, but warned that developers are underestimating how quickly that window could close. His comments also come as recent reports from quantum security firm Project Eleven warned that ‘Q-Day’, the point at which quantum computers become capable of breaking modern cryptography, could arrive as early as 2030.
“The biggest risk is complacency among developers,” he said. “Elliptic curve signatures won’t be broken in a few months, but chances are they will be broken in a few years. That leaves plenty of time to upgrade, but not enough to quibble.”