PIN, passphrase and face or fingerprint unlock

How you open the vault is the first thing between your photos and anyone else. Silo gives you three ways, and each does something a little different.

What it does

• PIN. At least 6 digits. It is free on every plan.
• Passphrase. A longer secret, at least 8 characters, which you type with the normal keyboard. A passphrase is a Pro feature.
• Face or fingerprint unlock. An optional shortcut, free on every plan, for opening the vault faster.

Your PIN or passphrase is not stored. Silo runs it through Argon2id, a deliberately slow method, to get the key that opens your vault.

How it works, step by step

1. Setup. You choose a PIN, enter it again to confirm, and then see your recovery phrase. You can choose a passphrase instead if you have Pro.
2. Unlocking. Enter the PIN or passphrase on the lock screen. Silo decrypts your keys in memory and opens the vault.
3. Face or fingerprint. In Settings, turn on Biometric unlock. Silo asks your phone to confirm it’s you. If the phone has no face or fingerprint set up, Silo tells you to set that up in the phone’s settings first.
4. After wrong attempts. Silo shows “Try again in” with a time, and makes you wait. This slows anyone guessing at the lock screen.
5. Changing it. In Settings, choose Change PIN or passphrase. Silo asks for your current one first.

If biometric unlock is ever reset, Silo says so and asks for your PIN or passphrase. You can turn it back on afterwards.

Which should you pick?

A 6-digit PIN is quick and fine against someone casually picking up your phone, especially with the wait after wrong tries. It is the weakest of the three against someone who can copy the files and guess offline with a powerful computer. A passphrase of several unrelated words or a long sentence is much harder to guess. If your vault holds things you would hate to lose control of, consider the passphrase.

Face or fingerprint is a convenience. Because it sits on top of the PIN, you don’t give up anything by turning it on, but a person who can make you unlock your phone with your face or finger can open Silo too. For that situation, keep it off.