User authentication in IT systems requires finding a balance between convenience and security. On one hand, users expect the login process to involve the fewest steps possible; on the other, it is essential to protect system access from unauthorized use. One way to manage security levels flexibly is through the trusted devices mechanism, which allows users to reduce the number of required login steps for recognized and secure devices.
The stricter the security policy, the more inconvenient it becomes for users—this is the eternal dilemma for system administrators. Long and complex passwords, frequent password changes, and additional authentication factors enhance security but also lead users to find ways to bypass procedures—such as writing passwords down in notebooks or saving them in browsers.
Trusted Devices – How Does It Work?
By default, Keycloak does not recognize or remember devices, meaning each session is treated independently. However, with extensions, support for trusted devices can be added, allowing users to skip certain steps during subsequent logins.
CTO of Inero Software, Waldemar Korłub, emphasizes:
"Hence the concept of trusted devices – the first time, we need to go through all the steps, but afterward, the application can, for example, skip asking for the two-factor authentication code."
Once a device is marked as “trusted,” the system can retain its status for a specified period, allowing for a simplified login process. However, the user may still be periodically asked to reauthenticate to ensure security.
Is remembering devices secure?
While the trusted devices mechanism improves user convenience, it also introduces additional risks. The biggest threat is the theft or loss of a device that has been previously marked as trusted.
As Waldemar Korłub points out:
"If the system does not require an additional authentication factor, an attacker could gain access to all stored applications. That’s why it is crucial for users to have control over their trusted devices—ideally through a panel where they can remove them at any time."
Introducing a device management panel and the option to revoke a device’s trusted status in case of loss are essential elements for ensuring security.
How can administrators control access in Keycloak?
Administrators can restrict the device remembering mechanism, for example, to specific networks or corporate devices.
Waldemar Korłub explains:
"We can limit this mechanism, for example, to computers within the local network—if users connect via the corporate VPN, we can recognize company-owned devices and enable the trusted devices option for them."
Thanks to such solutions, organizations can prevent users from assigning trusted status to personal devices that are beyond their control.
Trusted Devices in Keycloak – Key Takeaways
Trusted Devices Help Simplify Login but Require Proper Security Measures
The trusted devices mechanism in Keycloak allows users to skip certain authentication steps, such as entering a 2FA code. While this is a convenient solution that streamlines daily operations, it also requires the implementation of appropriate security measures. It is essential to define the validity period of a trusted device and monitor changes in login behavior to prevent misuse.
Administrators Can Control the Trusted Device Access Policy
Not every device should be marked as trusted, which is why administrators can restrict this feature to corporate computers or require a VPN connection. This helps prevent situations where a user assigns trusted status to a personal computer that the organization cannot control.
Device Management Panel Enhances Security
To give users greater control over their sessions, it is beneficial to implement a panel that allows them to review and remove trusted devices. This way, in case of device loss or suspected unauthorized access, users can quickly revoke granted permissions.
The Ability to Remove a Device Protects Against Account Takeover
If a device is lost or stolen and the system does not require additional authentication, an attacker could gain access to the user’s account. That’s why it is crucial to allow the removal of trusted devices at any time and enforce reauthentication. This approach provides greater flexibility while reducing the risk of unauthorized account access.
When Should You Use the Trusted Devices Feature in Keycloak?
The trusted devices feature in Keycloak enhances login convenience while maintaining a high level of security. This functionality is particularly useful in corporate environments and BYOD (Bring Your Own Device) models, where users regularly log in from the same devices.
Marking a device as trusted reduces the number of two-factor authentication (2FA) prompts, extends session duration, and allows for dynamic security policy adjustments, such as requiring reauthentication for suspicious logins. This approach helps mitigate the risk of account takeover—even if an attacker obtains a password and 2FA code—since logging in from a new device may trigger additional verification.
Implementing trusted devices in Keycloak enables organizations to strike a balance between security and user convenience.
The trusted devices mechanism in Keycloak enhances login convenience without significantly compromising cybersecurity. Proper implementation of the device remembering policy in Keycloak helps balance system security and user experience.
However, administrators should ensure that mechanisms are in place for managing the list of trusted devices and enforcing periodic verification of their status to mitigate potential security risks.