End-to-end encryption: passphrase and recovery code
End-to-end encryption means the key that opens your files is protected by a passphrase only you know. CDNShark stores the sealed key but cannot open it.
Choosing a passphrase
This is not your account password, and it is never sent to CDNShark. Use at least 12 characters. Nobody can reset it for you, so it needs to resist an offline guess — a password manager is the right place to keep it.
Your recovery code
At setup you are shown a 40-character recovery code, once. It is the only way back into your files if you forget your passphrase. Store it in a password manager, or print it and keep it somewhere safe — not inside the folder you are syncing.
If you forget your passphrase
On the sign-in screen choose I lost my passphrase, enter your recovery code, and set a new passphrase. Your files are not re-uploaded: only the wrapper around the key changes. You are issued a fresh recovery code, and the old one stops working.
Changing your passphrase
Go to Account → Encryption in the app. You will need your current passphrase, and you will be given a new recovery code.
If you lose both
The data is gone. There is no support request, no override and no back door — building one would defeat the purpose of the setting. If that trade is wrong for you, Client-side encryption gives you sealed storage with a safety net.