Google Quantum AI just published a landmark paper on quantum threats to every major blockchain. Beyond Bitcoin and Ethereum, no blockchain receives more coverage than Algorand, cited for live post-quantum deployments across signatures, state proofs, key r

Algorand has been mentioned 32 times and seems to be the leader in Post-Quantum security.

"Algorand (ALGO) provides an example of real-world deployment of PQC on an otherwise quantum-vulnerable blockchain. It launched in 2019 as a Pure-Proof-of-Stake blockchain for smart contracts and fast transactions. Smart 33 contracts on Algorand are written in popular high-level programming languages like Python and TypeScript and are compiled to assembly-like Transaction Execution Approval Language (TEAL) [246] which executes on the Algorand Virtual Machine (AVM) [247]. In addition to builtin single- and multi-signature transactions, Algorand supports stateless smart signatures and stateful smart contracts for DeFi applications. Algorand’s consensus and builtin transactions are based on quantum-vulnerable Ed25519 digital signature scheme. However, it has recently deployed post-quantum Falcon digital signatures [248, 249] for smart transactions and state proofs (cryptographic attestations of blockchain state for cross-chain integrations). Algorand has also made Falcon signature verification available as a TEAL primitive [250] to enable development of quantum-safe smart contracts for AVM. These PQC technologies are now publicly available: Algorand executed its first PQC-secured transaction in 2025 [62]. Moreover, Algorand enables users to change the private keys associated with their accounts [251]. While this mechanism does not provide full quantum security at present, it facilitates future PQC migration."