Fourthline’s Authentication products assess different factors to confirm the identity of existing clients (whose identity we have previously verified) to access your services.

You can use single authentication products to perform specific checks, or combine them into solutions for different levels of authentication or step-up flows.

We offer the following:

Product	Description
Biometric Authentication	Authenticate clients via a selfie photo and video.
Document Authentication	Authenticate clients via ID document photo(s).
Location Authentication	Authenticate clients via their geolocation and device metadata.
NFC Authentication	Authenticate clients via the NFC chip in their ID document.

Biometric Authentication

Fourthline checks if the client's selfie photo and video are authentic and compare them to those in their latest successful Identity Verification case to confirm they show the same person.

We perform the following checks on the selfie:

Check	Description	Required
Self-capture	We check that the client took the selfie and did the liveness check themselves with the camera of the device being used, and not otherwise inserted via captures, camera roll or library sources, or by any third party. We also check that only 1 face appears in the photo and video.
Image quality	We check the image quality of the selfie photo and video to ensure we can process them correctly.
Authenticity	We check that: • The selfie is authentic (not a photo of another photo or a screen). • The selfie video is authentic (not a video of a video or another screen), and that it shows a live client who is voluntarily participating, moves their head sufficiently, and isn’t wearing a physical or digital mask.
Face match	We check that the person in the selfie is the same person as in their original Identity Verification case. We compare the faces in both images and generate a percentage similarity score. Scores of 90% and up are accepted automatically. If the score is less than 60%, our human agents perform an additional four-eyes review.

We send the selfie back to you and request another if we detect that:

The selfie photo doesn't portray the client’s face.
The selfie photo is of another photo, even if the selfie video is authentic and shows motion.
The angle of the selfie photo doesn't let us compare it against the ID document portrait.
The quality of the selfie photo isn’t good, e.g.:
- The client's face is too far from the camera.
- The client’s eyes are closed.
- The client is wearing sunglasses, or a reflection off glasses is covering their eyes.
- The client isnt looking at the camera. In this case, we first check the device model before sending back, because it might still be acceptable.

Document Authentication

When an existing client gets a new ID document, they provide photos and we check that the document is fully visible, valid, authentic, supported, and in good condition with the required security features present. We then compare the new document data against the document in the client's latest successful Identity Verification case.

Fourthline performs the following checks:

Check	Description	Required
Self-capture	We check if: • The client took the document photos using the device camera, i.e. they weren't inserted via captures, camera roll or library sources, or by any third party. • Good quality photos of all required sides of the document are provided so that we can assess it correctly.
Personal data	Fourthline ensures all data groups are present and corrects any typos or misread data. We compare the following personal data from the new ID document against the expired document in the client’s latest successful case: • First and last names and nationality: If they don’t match, we advise asking the client the reason for the change, e.g. marriage, new citizenship. • Date and place of birth: If they don’t match, we recommend doing a Client Authentication or a new Identity Verification.
ID document validity	We check if: • The new ID document is currently valid and the client is the minimum age or over. • Both you and Fourthline support the document type and issuing country. • The document is in acceptable condition.
Security features	We check if all security features are present and clearly visible on the new ID document photos and video. If our AI agent can't detect them, a human agent reviews the images. All detected security features are included in the CDD Report and are viewable in the Case Review Portal.
Authenticity	We check if the new ID document is authentic, including that the photos aren't of other photos or screens.
ID document video	We record a 10-second video while the client takes photos of the new ID document. We check that the video and thereby the document itself are authentic. Fourthline human agents check for video deep fakes.
Chip data	If you uploaded data from the ID document NFC chip, Fourthline compares the following personal data from the chip against the MRZ and VIZ, relying most on the chip data quality: • First and last name(s) and full legal name • Date of birth and place of birth (if present) • Gender • Document number and type, issuing country, issue date (if present) and expiry date • Nationality We check if the color portrait of the client on the chip matches the monochrome portrait on the ID document.
Chip portrait	We check if the color portrait of the client on the chip matches the monochrome portrait on the ID document.

More information

For the complete list of supported ID documents, request our CDD Policy from your implementation manager.

Location Authentication

Fourthline checks if the geolocation and metadata of the client’s device are valid, authentic, and uncompromised. We then compare them to a previous case.

We perform the following checks on the geolocation and device metadata:

Check	Description	Required
Self-capture	We check that the client gave permission to share their geolocation and that the geolocation comes from the device being used, not from any other source.
Geolocation	We extract the geolocation data and check that all your required data groups (e.g. device, ID document photos and video, selfie photo and video) are present and valid. We check it isn't in a prohibited country. Our human agents investigate any geolocation outside of Europe.
IP address	We check if the IP address is valid.
Metadata	We check the device language, region, and model, as well as the country code of the phone number are present and sufficiently complete. We compare this metadata to the IP address and geolocation data to conclusively determine the client's current location.
Fraud hot spot	We check if the home address the client provided is close to a location we know to be associated with financial crime. Fourthline human agents investigate hot spots.
Address	We check if the home address the client provided is: • Complete, including street name, number, postal code, city and country • Valid and in a residential area, not an industrial site • In a country you support • Not a PO box address or in a prohibited country

More information

For the complete list of supported countries and territories, request our CDD Policy from your implementation manager.
The list of prohibited countries may change over time, e.g. depending on European sanctions.

NFC Authentication

We check if the NFC chip embedded in the ID document is authentic and uncompromised, ensure that all data groups are available, extract and verify the data against other data sources, e.g. in combination with Document Photo or Document Liveness.

We unlock the chip using either Document Photo/Liveness or the card access number (CAN) provided by the client.

Near Field Communication (NFC) — NFC Authentication

Fourthline performs the following checks:

Check	Description	Required
Chip data	If you uploaded data from the ID document NFC chip, Fourthline compares the following personal data from the chip against the MRZ and VIZ, relying most on the chip data quality: • First and last name(s) and full legal name • Date of birth and place of birth (if present) • Gender • Document number and type, issuing country, issue date (if present) and expiry date • Nationality We check if the color portrait of the client on the chip matches the monochrome portrait on the ID document.
Chip portrait	We check if the color portrait of the client on the chip matches the monochrome portrait on the ID document.

Next steps

Learn how to combine these products for your use cases into Authentication solutions.

Get in touch

Top of page