SEED PHRASE SECURITY EXPLAINED: BACKUPS, STORAGE & RECOVERY

A seed phrase, also known as a recovery phrase, mnemonic phrase, or backup phrase, is a series of 12, 18 or 24 words generated when setting up a cryptocurrency wallet. This phrase is the key to accessing your digital assets, and controlling your funds depends entirely on keeping it secure. If someone accesses your seed phrase, they can gain full control over your wallet without the need for passwords, biometrics, or two-factor authentication.

The seed phrase functions as a master key that regenerates your private keys and therefore, your wallet. It’s a core component of how non-custodial wallets (such as MetaMask, Ledger, and Trezor) operate. It’s also crucial in decentralised finance (DeFi) and self-custody, where users take full responsibility for the security of their investments.

Because the seed phrase is unrecoverable through customer support or central authorities, losing it means irrevocable loss of access to the funds in the associated wallet. Equally, leaking your seed phrase to malicious actors can result in instant theft.

In this guide, we explain how to protect your seed phrase through proper backup, storage techniques and recovery planning strategies.

Backing up your seed phrase is a fundamental step in securing your cryptocurrency holdings. The importance of a robust and secure backup cannot be overstated, as your entire digital wealth hinges on your ability to recover the seed phrase reliably.

Write it down—never digitise

The best practice for backing up your seed phrase is to write it down by hand on paper (or metal) and avoid storing it digitally. Digital backups (e.g., screenshots, cloud storage, documents) expose your seed phrase to malware, phishing schemes, and unauthorised access via compromised devices or online accounts. Writing it down ensures it remains offline and immune to cyberattacks.

Use multiple physical copies

Consider creating multiple handwritten copies of the seed phrase and storing them in separate, secure locations. This adds redundancy in case one copy is destroyed (such as through fire or water damage) or lost. However, be strategic about who can access these copies and where they are kept.

Use fire-resistant materials

Paper backups are vulnerable to environmental damage. Several companies offer fireproof metal plates (e.g., Cryptosteel, Billfodl, SteelWallet) where you can engrave or assemble your seed phrase using stamped words or characters. Metal wallets provide durability and resilience to flood, fire, and decay, making them widely recommended among security experts.

Encrypted digital storage (advanced users only)

If you have advanced technical know-how and employ strict operational security (OpSec), you could opt for an encrypted cold storage solution. This might include PGP-encrypted USB sticks or air-gapped devices. However, this route involves higher risk for most users, as poor encryption practices or hardware failure could result in irretrievable access.

Test your recovery process

Once you've backed up your seed phrase, it's good practice to validate the recovery process. Use another wallet to try recovering a test wallet with only negligible funds. This ensures the phrase was written correctly and the backup is functional.

Proper backup is the first layer of defence. Without it, even the most sophisticated wallet or security setup becomes irrelevant. Treat your seed phrase as you would a valuable physical asset such as deeds or gold bars.

After backing up your seed phrase, the next critical step is determining where to store it. The goal is to balance strong security with reliable accessibility. Your storage decisions should be informed by your threat model—which covers risks such as physical theft, natural disasters, or forgetting the location of your backup.

Secure and discrete physical locations

A common method is to store the written or metal-engraved seed phrase in a safe or lockbox. Ideally, this should be installed in an area with a low probability of flood or fire. Using a high-grade fireproof safe is even better. Location selection matters—consider locations that are inconspicuous and not easily identifiable as high-value targets (avoid labelling boxes as ‘crypto backup’, for example).

Geographic decentralisation

Keeping multiple copies in different physical locations is a useful tactic to avoid a single point of failure. For instance, you might store one copy at home, one at a family member’s house, and another in a safety deposit box. Choosing geographically separate areas adds protection from local natural disasters or home break-ins.

Consider trusted third parties carefully

You may choose to entrust your seed phrase backup to a third party—such as a solicitor, family member, or a professional vaulting service. This introduces risks around trust, incompetence, or coercion, so it should only be done under legal guidance and with reliable parties. Splitting the phrase (e.g., 12-word split into two 6-word groups) can add security, but also increases complexity.

Shamir’s Secret Sharing

An advanced and mathematically secure technique is Shamir’s Secret Sharing protocol, supported by some hardware wallets. It breaks the seed into multiple shares, requiring a defined subset to reconstruct the phrase. For example, a 3-of-5 Shamir threshold means five shares exist, and any three can recover the phrase. This allows redundancy with enhanced confidentiality for each storage node.

Don’t rely on memory

While it may feel secure to memorise your seed phrase, it’s dangerously unreliable and vulnerable to memory lapses or psychological trauma. In practice, memorisation should only supplement—never replace—a physical backup. If you forget even one word, the entire phrase becomes unusable.

Regular audits and updates

Periodically audit your seed phrase storage setup. Check that stored materials haven't degraded, the locations remain secure, and access procedures remain clear. Avoid accessing the seed phrase unnecessarily to reduce exposure, but ensure the knowledge to recover it remains updated over time.

Seed phrase storage is not a one-time task—it’s an ongoing responsibility dependent on privacy, safety, and operational risks.