--- title: How to protect your crypto from quantum computers description: Four steps that cut your quantum risk today, what a wallet can and cannot fix, and how to check whether the chain you hold is actually ready. url: "https://hardyindex.com/guides/how-to-protect-crypto-from-quantum-computers" section: What to do about it updated: 2026-08-12 methodology_version: 1.1 --- # How to protect your crypto from quantum computers **You cannot make an exposed chain quantum-safe yourself, but you can cut your risk today. Check how ready your chain is, stop reusing addresses, keep long-term holdings in a wallet whose keys you control, and take your chain's post-quantum upgrade when it ships. Here is the order to do it in.** *As of 12 August 2026. This is a security-readiness assessment, not investment advice.* If you hold crypto and the quantum headlines have been bothering you, this is the practical version. Four steps, in order, with the limits of each one stated. ## What does being exposed actually mean for your coins? Being exposed means your public key is already visible on a public blockchain, where a future quantum computer could use it to calculate your private key. It is not a warning about your wallet software or your password. It is about what the chain has already published about you. Here is the version that usually lands. If you have ever spent from an address, that address has shown its public key to the world, permanently. If you have received to the same address more than once, anything still sitting there is behind a key that is already out. On some chains it is worse by design. Solana and Algorand addresses are derived directly from the public key, so every account is exposed from the moment it exists, whether it has spent or not. And on Bitcoin the scale is measurable. Deloitte found roughly 4 million BTC at exposed addresses, about 25% of supply, while Galaxy Digital estimated roughly 7 million and Glassnode 6.04 million, or 30.2%. If you hold Bitcoin at an address that has spent, you are inside that number. ## What can you fix yourself, and what can you not? You can control where your coins sit and which addresses have revealed their keys. You cannot change the signature scheme your chain uses, and no wallet, product or service can do that for you. That division is the whole of this page. It is worth being blunt about it, because the market is filling up with products that blur the line. A wallet can protect its own firmware with post-quantum cryptography and still sign your Bitcoin transaction with ECDSA, because ECDSA is what Bitcoin accepts. So the honest picture is two-sided. The part you control is worth doing today and costs nothing. The part you do not control is the chain's migration, and your job there is to know where your chain stands and to move when it moves. The gap between those two states is smaller than most people expect. Unsure and possibly exposed, versus checked, tidied and ready to migrate, is about twenty minutes of work. ## How to protect your crypto from quantum computers, step by step Four steps, in order. The first three you can do today, and the fourth is the one that ends the risk when your chain is ready. 1. **Check how ready your chain is.** Look up everything you hold on [the Hardy Index](https://hardyindex.com/), which scores 23 major chains from 0 to 100. Tier 1 and Tier 2 chains have post-quantum signatures on mainnet today. Tier 4 and Tier 5 chains do not, and Tier 5 has no published plan at all. 2. **Stop reusing addresses.** Use a fresh receiving address each time. On chains where the address is a hash of the public key, an address that has never spent has never revealed its key. Google's Quantum AI team recommends exactly this: refrain from exposing or reusing vulnerable wallet addresses. 3. **Hold long-term funds in a wallet whose keys you control**, with the recovery phrase written down and kept offline. This does not make your chain quantum-safe. What it does is put the timing in your hands, so you can migrate the day your chain supports it rather than waiting for an exchange to decide. 4. **Take the post-quantum migration when your chain ships it.** This is the step that actually removes the risk. On most chains it will look like a wallet update and a move to a new address type. Algorand, for example, has published a dated plan for Falcon accounts derivable from existing seed phrases. > **If you hold on an exchange.** Coins on an exchange are behind keys the exchange controls, so steps two and three are not yours to take. That is not automatically wrong, and it does mean your quantum exposure depends on a migration plan you cannot inspect. It is worth knowing which of the two positions you are in. ## Which wallet should you use? For most people the honest answer is a reputable hardware wallet, chosen for the reasons hardware wallets have always been chosen, with quantum readiness as a tiebreak rather than the reason. No wallet on the market today makes a quantum-vulnerable chain safe, and the good ones say so themselves. The exception is a wallet for a chain that is already post-quantum. If you hold on the Quantum Resistant Ledger, your signatures are hash-based today. That is a property of the chain, not of the wallet, which is the point this whole page keeps returning to. ### The options we would look at These are editorial choices, not paid placements, and each one is listed with what it does not fix. [Quantum-safe wallets, compared in full](https://hardyindex.com/guides/quantum-safe-wallets) goes deeper on how they differ. > **Disclosure.** Some links below are affiliate links, which means the Hardy Index may earn a commission if you buy. They never affect a rating, a score or a tier. [How we make money](https://hardyindex.com/how-we-make-money). #### Trezor Safe 7 (affiliate link) A hardware wallet that keeps your private keys on a device rather than on an internet-connected computer. **Why we would look at it.** It is the first hardware wallet to put post-quantum cryptography into the device itself. Trezor documents its boot process and firmware updates as verified with SLH-DSA-128, and its device attestation certificate as using ML-DSA-44, both NIST-standardised schemes. **What it does not fix.** This protects the device, not your coins. Trezor states plainly that the Safe 7 "is not quantum-proof because full protection requires that the blockchains also upgrade". Transaction signing still uses whatever scheme your chain uses. [Visit Trezor Safe 7](https://trezor.io/trezor-safe-7). Source: [Trezor Safe 7: the first quantum-ready hardware wallet](https://trezor.io/guides/trezor-devices/trezor-safe-7/the-first-quantum-ready-hardware-wallet), Trezor. #### Ledger (affiliate link) A hardware wallet range built around a certified secure element, with broad chain and app support. **Why we would look at it.** Ledger has published post-quantum work of its own: ML-KEM and ML-DSA are now in the Ledger SDK and embedded OS, and its Donjon security team publishes research on running these schemes inside constrained secure elements. **What it does not fix.** Those algorithms sit in the SDK, not in blockchain transaction signing, and Ledger notes that the first version ships with no side-channel countermeasures. A Ledger does not make a quantum-vulnerable chain safe. [Visit Ledger](https://www.ledger.com/). Source: [Post-quantum cryptography in the Ledger SDK](https://www.ledger.com/blog-post-quantum-cryptography-ledger-sdk), Ledger. #### The QRL wallet (earns us nothing) The wallet for the Quantum Resistant Ledger, the highest-rated chain in the Hardy Index. **Why we would look at it.** This is one of the few wallets where the signature protecting your funds is genuinely post-quantum today. Every QRL account is secured by XMSS, a hash-based scheme approved by NIST in SP 800-208, with no elliptic-curve fallback on the network. **What it does not fix.** XMSS is stateful, so the wallet has to track which one-time keys have been used, and reusing one can expose funds. QRL is also a small network by liquidity and developer activity. This earns the Hardy Index nothing. [Visit The QRL wallet](https://www.theqrl.org/). Source: [The Quantum Resistant Ledger](https://www.theqrl.org/2/), The Quantum Resistant Ledger. ## What should you avoid doing? Avoid anything that treats the quantum threat as a reason to trade. Selling into a headline, buying a token because its marketing says quantum-proof, or moving funds in a hurry all create real, immediate risks in exchange for a theoretical future one. - **Do not buy a coin because it claims to be quantum-proof.** The Hardy Index holds back chains whose claims cannot be verified against a primary source, and three currently sit in that category. Marketing outruns deployment in this sector more than in most. - **Do not pay for a service that promises to quantum-proof coins on a chain that has not shipped post-quantum signatures.** That is not something a third party can deliver. - **Do not rush a large transfer.** Losing coins to a mistyped address or a phishing site is a risk today. Quantum computers are not. - **Do not assume a hardware wallet has solved it.** It protects your keys from the attacks that actually happen now, which is worth having, and it does not change your chain's signature scheme. The Hardy Index takes no view on what anyone should buy, sell or hold, and it never will. It rates how ready chains are, and the ratings are the same whether or not a company pays us anything. [How we make money](https://hardyindex.com/how-we-make-money) sets out that arrangement in full. ## Frequently asked questions ### Can I make my crypto quantum-proof today? Not by yourself, on most chains. The signature scheme is set by the blockchain, so a chain using ECDSA or Ed25519 stays quantum-vulnerable until it ships an upgrade. What you can do today is reduce exposure: use fresh addresses, move funds off addresses that have already spent, and hold keys you control so you can migrate immediately when your chain is ready. ### Does moving my coins to a new address help? Yes, if the old address had already revealed its public key and the new one has not. Moving does not un-publish the old key, and it does mean an attacker who eventually breaks that key finds nothing behind it. On chains where the address is derived from the public key, such as Solana and Algorand, this does not help, because every address is exposed from creation. ### Is a hardware wallet enough to protect against quantum computers? No, and the manufacturers agree. Trezor states that the Safe 7 "is not quantum-proof because full protection requires that the blockchains also upgrade". A hardware wallet protects your private key from malware and phishing, which are the attacks that drain wallets today. It cannot change the signature scheme your chain uses. ### Should I move my crypto to a quantum-resistant chain? That is a decision the Hardy Index will not make for you, because it involves everything else you care about in an asset, not just cryptography. What the Index can tell you is which chains rate highest on readiness, and that Quantum Resistant Ledger leads at 92.0 out of 100. Moving between chains carries real risks of its own, which [moving to a quantum-ready chain](https://hardyindex.com/guides/moving-to-a-quantum-ready-chain) covers. ### How will I know when my chain has migrated? Your chain profile on the Hardy Index carries a sourced roadmap and a last-reviewed date, and score changes are logged in the public changelog with the reason and the source. A migration that ships moves the chain up a tier, which is the visible signal to watch for. ## Where to go next - [The Hardy Index ranking](https://hardyindex.com/): Look up every chain you hold, in one table. - [Quantum-safe wallets, compared](https://hardyindex.com/guides/quantum-safe-wallets): What is genuinely post-quantum in each wallet, and what is marketing. - [Moving to a quantum-ready chain](https://hardyindex.com/guides/moving-to-a-quantum-ready-chain): How a move works, and when it is the wrong answer. - [Is my crypto safe from quantum computers?](https://hardyindex.com/guides/is-my-crypto-safe-from-quantum-computers): The background, if you want the threat explained first. - [How the Hardy Index makes money](https://hardyindex.com/how-we-make-money): What earns, what does not, and why it can never touch a rating. ## Sources 1. [Safeguarding cryptocurrency by disclosing quantum vulnerabilities responsibly](https://research.google/blog/safeguarding-cryptocurrency-by-disclosing-quantum-vulnerabilities-responsibly/): Google Research (primary, checked 12 August 2026) 2. [Trezor Safe 7: the first quantum-ready hardware wallet](https://trezor.io/guides/trezor-devices/trezor-safe-7/the-first-quantum-ready-hardware-wallet): Trezor (primary, checked 12 August 2026) 3. [Post-quantum cryptography in the Ledger SDK](https://www.ledger.com/blog-post-quantum-cryptography-ledger-sdk): Ledger (primary, checked 12 August 2026) 4. [Algorand post-quantum roadmap](https://algorand.co/technology/post-quantum): Algorand Foundation (primary, checked 12 August 2026) 5. ['That is the end of Bitcoin': the quantum race for $470 billion](https://www.forbes.com/sites/boazsobrado/2026/08/02/that-is-the-end-of-bitcoin-the-quantum-race-for-470-billion/): Forbes (secondary, checked 12 August 2026) --- Cite as: The Hardy Index, "How to protect your crypto from quantum computers", https://hardyindex.com/guides/how-to-protect-crypto-from-quantum-computers, as of 12 August 2026.