From decrypt by Jose Antonio Lanz

Solana developers have created a quantum-resistant vault that uses a decades-old cryptographic technique to protect users' funds from potential quantum computer attacks. The solution, called Solana Winternitz Vault, implements a hash-based signature system that generates new keys for each transaction.

The vault addresses a known vulnerability in blockchain technology: quantum computers could potentially crack the cryptographic algorithms that secure digital wallets. When users sign transactions, they expose their public keys, which theoretically could be used by sufficiently powerful quantum computers to derive their private keys through the Elliptic Curve Digital Signature Algorithm. (These stories might help you understand a bit more about that topic.)

The vault currently exists as an optional feature, not a network-wide security upgrade, so there is not really a fork in sight. This means, users would need to actively choose to store their funds in these Winternitz Vaults instead of regular Solana Wallets for their funds to be quantum proof.

"The irony is not lost on me that we are using Lamport's work to secure lamports," Dean Little, the developer behind the project, wrote, explaining that the vault uses a cryptographic protocol called Winternitz One-Time Signatures.

The system works by generating 32 private key scalars and hashing each one 256 times to create a public key. Instead of storing the entire public key, the program stores only a hash of it for verification. Each time a transaction occurs, the vault closes and opens a new one with fresh keys.

If all this jargon sounds weird, think about this inaccurate but close-enough analogy: If you ask for a new credit card every single time you pay, no hacker will be able to guess its number before you pay.

"While nobody can hash backwards, anyone can hash forwards from a previous value," Little explained. This means each signature has about a 50% chance of being compromised for future transactions—which is why the vault generates new keys after each use.

Quantum resistance before it was cool

While Solana's implementation marks a significant step for the network, quantum-resistant cryptography in blockchain isn't new. David Chaum, often called the "godfather of crypto," launched Praxxis in 2019 specifically to address quantum computing threats. His team developed a consensus protocol that promised to overcome scalability, privacy, and security challenges while remaining resistant to quantum attacks.

The conversation around quantum resistance in crypto has been around for a while. It gained momentum after Google's announcement of achieving "quantum supremacy" in 2019. Their 53-qubit computer demonstrated unprecedented computational power, performing calculations in 200 seconds that would take traditional computers over 10,000 years. More recently, Google’s Willow chips were capable of achieving in 5 minutes calculations that would take 7 septillion years using the fastest supercomputers currently available.

However, Cornell University researchers noted that breaking a 160-bit elliptic curve cryptographic key would require about 1,000 qubits—far more than what's currently available. Despite this, several blockchain projects aren't waiting. QAN, for instance, claimed to achieve "quantum hardness" in its beta stage, while other protocols have been quietly upgrading their cryptographic foundations.

Some experts argue that quantum computing power could grow at a double exponential rate—this is known as Neven’s Law. This forecast has pushed more blockchain developers to implement quantum-resistant solutions, even as full-scale quantum computers remain years or decades away from posing a real threat to current cryptographic standards.

So focusing on quantum resistance may seem like an overkill for many crypto projects, but Web3 developers are all about being two steps ahead. If you don’t believe us, ask why chains that don’t process more than a few hundreds of transactions per second dedicate so many resources to support thousands and even millions of transactions per second.