Introducing TzEL: Private Post-Quantum Payments, Live on Tezos Testnet

New rollup employs advanced cryptography to protect private transactions in a post-quantum world

London, UK—14 May, 2026— A new post-quantum privacy solution has launched on a testnet for the Tezos blockchain. TzEL is designed to enable private payments that remain fully private, even as advances in quantum computing compromise the security of the elliptic curve cryptography used for privacy on blockchains today.  It is the first working prototype of a system designed to keep payments private in a post-quantum world.

In recent months, concerns around the quantum threat facing blockchains have increasingly moved from academic curiosity into practical risk management. Privacy on blockchains today relies on elliptic curve cryptography that quantum computers will break. What’s more, while existing systems can keep a payment private today, the associated encrypted note payloads and memos are permanently recorded on-chain, presenting malicious actors with a real opportunity to harvest data now for decryption later. 

TzEL neutralizes this threat by implementing quantum-resistant cryptography for both payments and the associated data. It ensures users can continue to transact privately, with full control over who can view transaction data through features like encrypted payment memos, viewing keys, and detector keys.

Commenting on the launch, Arthur Breitman, co-founder of Tezos, said, “Private transactions have a long memory: the data encrypted today may still be around when tomorrow’s attacks arrive. With TzEL, we set out to build a shielded ledger for Tezos whose privacy stack is post-quantum end to end.”

One particular technical challenge involved in building a post-quantum privacy system has been the size of the cryptographic proofs. The quantum-resistant zk-STARK proofs used by TzEL are around 300KB – much larger than currently used privacy proofs – which make post-quantum private systems economically and technically prohibitive for many blockchains.

TzEL avoids this obstacle by utilizing Tezos’ built-in Data Availability Layer (DAL). Integrated into the Tezos protocol in 2024, the DAL significantly increases the amount of transaction data that can be published on-chain, making it possible to offer a full private transaction stack without congesting the network.

While still in development, and while Tezos itself is still only beginning to transition to post-quantum cryptography, TzEL demonstrates that private, post-quantum transactions are achievable today, and points toward a future where long-term transaction privacy is the baseline, not the exception. Learn more about TzEL at http://tzel.tezos.com.

About Tezos

Tezos is an open-source and energy-efficient blockchain designed to empower institutions, developers, and businesses, and facilitate value transfer in a digital environment. It is designed for the scalable deployment of decentralized applications. As one of the first Proof of Stake blockchains, Tezos is globally supported and valued for its strong governance, long-term upgradability, and smart contract capabilities. For more information about Tezos, visit http://www.tezos.com.