Ledger's Chief Technology Officer Charles Guillemet warns that while quantum computers capable of cracking elliptic curve cryptography are not an immediate threat, preparations must begin immediately. He points out that Bitcoin public keys are often exposed due to spending or early transactions, and in future quantum attack scenarios, an estimated 70 million Bitcoins could be at risk. Post-quantum cryptography, such as hash-based or lattice-based schemes, offers a solution, but implementing these schemes securely in hardware signers still faces technical challenges. Ledger is conducting related experiments, but memory and computational costs remain bottlenecks. Ethereum co-founder Vitalik Buterin recently also outlined the network's roadmap for quantum resistance.