YubiKey FIPS (4 Series)


Note: This article lists the technical specifications of the YubiKey FIPS (4 Series). If you're looking for deployment considerations, refer to this article. If you're looking for a usage guide, refer to this article. For a comparison between the YubiKey FIPS Series and the rest of our products, please see this page.

The YubiKey FIPS (4 Series) is a FIPS 140-2 certified (Overall Level 2, Physical Security Level 3) device based on the YubiKey 4. It has five distinct sub-modules, which are all independent of each other and can be used simultaneously. Note: Some software such as GPG can lock the CCID USB interface, preventing another software from accessing sub-modules that use that mode.


The YubiKey FIPS (4 Series) uses a USB 2.0 interface. All of the sub-modules are available through this interface.



The OTP sub-module contains two programmable slots, each can hold one of the following credentials:

  • Yubico OTP
  • HMAC-SHA1 Challenge-Response
  • Static Password

USB Interface: OTP


The U2F sub-module can hold an unlimited number of U2F credentials and is FIDO certified.

USB Interface: FIDO


The YubiKey FIPS series can hold up to 32 OATH credentials and supports both OATH-TOTP (time based) and OATH-HOTP (counter based). Accessing this sub-module requires Yubico Authenticator.

USB Interface: CCID

PIV (Smart Card)

This sub-module provides a PIV compatible smart card. On Windows, the smart card functionality can be enhanced with the YubiKey Smart Card Minidriver.

Supported Algorithms:

  • RSA 2048
  • ECC P256
  • ECC P384

USB Interface: CCID


This sub-module implements version 2.0 of the OpenPGP Smart Card specification which can be used with GnuPG. For key sizes over 2048 bits, GnuPG version 2.0 or higher is required.  

Supported Algorithms:

  • RSA 2048
  • RSA 3072
  • RSA 4096

USB Interface: CCID

Physical Specifications

Form Factor

Connector: USB-A
Dimensions: 18mm x 45mm x 3.3mm
Weight: 3g


Operational range: 0 °C to 40 °C (32 °F to 104 °F)
Storage range: -20 °C to 85 °C (-4 °F to 185 °F)