JUST IN: Dogecoin Experiments with Post Quantum Signatures Without Altering Its Current Protocol. The Dogecoin Foundation is testing a double-transaction system on the mainnet using Falcon512 to secure signatures against the quantum era.

Ed Tubbs, senior software engineer at the Dogecoin Foundation, announced on April 10 that his team is conducting experiments on the Dogecoin mainnet to attach post-quantum signatures to ordinary transactions.
The mechanism uses Falcon-512, a quantum resistant signature algorithm, and operates without modifying the network's base protocol.