A statement from Nextcloud said the Nitrokey Pro 2 and Nitrokey Storage 2 devices had both been verified to work easily with Nextcloud’s one-time passwords for secure two-factor authentication.
This would protect user accounts if passwords were compromised, Additionally, the USB keys have a password manager, a cryptographic key store for email encryption and SSH administration.
The Nitrokey Storage 2 also contains an encryption mass storage drive with the option of hidden volumes.
"Our collaboration will deliver smooth inter-operability between our solutions, enabling customers to have a fully transparent, verifiable authentication process."
Nextcloud managing director Frank Karlitschek said: "Security is a growing concern in the industry and second-factor technologies are helpful in further securing authentication.
"Together with Nitrokey we can continue to advance the state-of-the-art in reliable, safe sharing and collaboration."
The statement said the two companies had agreed to collaborate to develop FIDO2 support in their systems, ensuring Nitrokeys could be used to securely log in to Nextcloud systems.
With FIDO2 support, a technology based on the W3C’s Web Authentication (WebAuthn), users will be able to log in without passwords with their Nitrokey. This is likely to be ready in time for an announcement at Nextcloud's conference in September in Berlin.