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What is passwordless authentication?
Passwordless authentication is a sign-in method that verifies a user without a password. The password is not made longer or hidden better. It is taken out, and a different kind of proof takes its place.
That difference is larger than it sounds. A password is a shared secret: the user remembers one copy, the server stores another, and anything that reads either copy can become the user. A passwordless method replaces the shared secret with something a user cannot type into the wrong box.
How does passwordless authentication work?
Every passwordless method answers the same question in the same shape. The server sends a challenge, a device the user holds answers it, and the answer proves something the server can check but an attacker cannot guess.
What changes between methods is the kind of proof and where it is kept. Most methods hold the secret on one device and never send it, so the network carries a signature or a token instead of the thing that produced it.
Possession, not memory
The factor is a thing the user holds: a phone, a hardware key, or a device registered earlier. A lost device is a support problem, but it cannot be leaked in bulk the way a password table can.
Inherence, when the person matters
A biometric trait such as a face proves who is present, not only what is held. It is the only factor that still means something when a device is stolen while unlocked.
The device answers a challenge
The server sends a fresh challenge, the device signs it or returns a one-time proof, and the server checks that answer against a public key or a prior enrollment. The secret itself never crosses the network.
Binding is what makes it strong
Most methods tie the credential to one device, and often to one site. That binding is the reason a captured message cannot be replayed from somewhere else.
What are the benefits of passwordless authentication?
The security argument and the user argument point the same way here, which is rare in identity work. Removing the password takes out the one credential that phishing kits, credential-stuffing lists, and helpdesk resets all depend on.
Expect the operational gain before the security gain. Password resets are usually the largest single ticket category an identity team carries, and that number moves in the first month.
Nothing to steal in bulk
There is no password database to dump and no reused password to try against your login page. Somebody else's breach stops being your incident.
Fewer resets to support
A user has no secret to forget, so the reset queue and the account-recovery call both shrink. Recovery becomes a device problem, which is easier to verify than a memory problem.
Strength comes from the method
You stop writing rotation rules and complexity rules that users route around. The security property holds without asking anyone to behave well.
What are common types of passwordless authentication?
Passwordless is a category, not a security level. The methods below all remove the password, and they do not all stop the same attacks.
Choose by the attack you are actually trying to stop. If your losses come from phishing, only the device-bound methods help. If they come from reset cost, even the weaker methods pay for themselves.
- FIDO2 and passkeys: a key pair bound to one device and one site domain.
- On-device biometrics: a face or a fingerprint that unlocks a device-bound key.
- Magic links: a one-time URL sent by email.
- One-time codes: a numeric code from an app, an email, or an SMS.
How does SenseCrypt do passwordless authentication?
SenseCrypt is a passwordless identity provider (IdP) from Seventh Sense. A user enrolls from a photo already on file, then signs in by face. There is no password to set at enrollment and none behind it as a fallback, which is deliberate: a fallback password puts back the credential the design just removed.
The face check runs on the user's own device. What travels to the server is a single-use face token, not an image and not a template.
Enroll from a photo on file
The record you already hold becomes the enrollment, so a user does not start with a separate registration ceremony before they can sign in.
The match runs on-device
Capture and comparison happen on the phone. The server stores no face image and no face template, so there is no face gallery to breach, subpoena, or migrate later.
One token per sign-in
Each ceremony spends one face token and that token is then dead. The tokenization is patent-pending.
No shared code at sign-in
The user types nothing and reads nothing out. A one-time PIN appears once in the whole lifecycle, when a new device is bound, and it is emailed plus sent by SMS when a mobile number is on file.
Frequently asked questions
Is passwordless authentication more secure than passwords?
Yes, in most cases. Passwordless authentication takes out the shared secret that attackers target. Many methods also resist phishing.
Does passwordless authentication always use biometrics?
No. A passkey or a hardware key needs no biometric trait. Biometric factors, such as a face, are one option among several.
How does SenseCrypt do passwordless sign-in?
SenseCrypt enrolls a user from a photo on file. The user then signs in by face. Face matching runs on-device, and SenseCrypt stores no face image and no face template.
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