What are digital keys?
Definition
Digital keys are secret values that a cryptographic algorithm uses to lock, unlock or sign data. Whoever holds the right key can read protected data or prove a message came from them.
- Category
- Security
- Also called
- cryptographic keys, encryption keys
- Last updated
NIST defines a key as a parameter used with a cryptographic algorithm that determines how the algorithm operates. In plain terms, the algorithm is the lock and the key is what makes it open or close. The same lock design can be public knowledge. What stays secret is the key.
Keys do two common jobs. The first is encryption: data is scrambled with a key so only someone with the matching key can read it. The second is signing: NIST describes a digital signature as the result of a cryptographic transformation of data that lets someone verify who it came from and that it wasn't altered. Creating and checking that signature both depend on keys.
Where you meet them
You use digital keys every time a site loads over HTTPS, when your phone encrypts its storage, or when a password manager unlocks your vault. Most of it happens without you seeing a key at all. Some keys you do handle yourself, such as a recovery key for a device or an account.
Why it matters
A strong algorithm doesn't help if the key leaks. If someone copies your recovery key from an unlocked note, or a company stores keys next to the data they protect, the lock is effectively open. For an ordinary person the practical point is simple: a digital key is only as safe as where you keep it.
Digital keys vs. passwords
A password is something you remember and type. A key is usually a long random value that software generates and stores for you. Many systems derive a key from your password, which is why a weak password weakens the encryption behind it.
How to protect yourself
- 1
Keep recovery keys offline
Print recovery keys or save them in a password manager. Don't leave them in email, screenshots or an unlocked notes app.
- 2
Use a strong, unique password
If a key is derived from your password, a guessable password makes the key guessable too.
- 3
Turn on device encryption
Current phones and laptops offer it in settings. It uses keys you never have to handle.
- 4
Replace keys after a leak
If a key, token or recovery code was exposed, generate a new one and revoke the old one.
See where your personal data is exposed
Serus finds it on data brokers and people-search sites and removes it.
Frequently asked
What is the difference between a public key and a private key?
Some systems use a pair of keys. The public key can be shared freely and is used to lock data or check a signature. The private key stays secret and is used to unlock data or create a signature.
What happens if I lose my digital key?
It depends on the system. Some let you recover access with a backup or recovery key. Others have no way back, and the data stays locked. Store a backup before you need it.
Is a digital key the same as a digital signature?
No. A signature is the result of using a key on data. The key is the secret input, the signature is the output that others can verify.
Sources
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