Firmware Overview

The firmware version on a YubiKey or a Security Key determines whether or not a feature or a capability is available to that device. The quickest and most convenient way to determine your device’s firmware version is to use either the Yubico Authenticator with its intuitive and easy-to-use (GUI) interface or ykman the lightweight command line (CLI) software package installable on many OSs.

Note

Yubico periodically updates its firmware to take advantage of features and capabilities introduced into the ecosystem. YubiKeys are programmed in Yubico’s facilities with the latest available firmware. Once programmed, YubiKeys cannot be updated to another version. The firmware cannot be altered or removed from a YubiKey.

Form Factors Available per Firmware Version
Form Factors


Firmware Versions
5.7.x 5.5.x 5.4.x 5.3.x 5.2.x 5.0.x
USB-A Yes Yes Yes Yes Yes Yes
USB-A + NFC Yes Yes Yes Yes Yes Yes
USB-A Nano Yes Yes Yes Yes Yes Yes
USB-C Yes Yes Yes Yes Yes Yes
USB-C + NFC Yes Yes Yes Yes Yes  
USB-C Nano Yes Yes Yes Yes Yes Yes
Lightning + USB-C Yes Yes Yes Yes    

YubiKey 5 Series

The features, capabilities, and enhancements of the YubiKey 5 Series that are dependent on firmware version are listed below in the Firmware Capability Matrix.

5.7.4 Firmware - FIPS Series

The 5.7.4 new features include:

  • Submission to submitted to NIST’s Cryptographic Module Validation Program for FIPS 140-3 validation.
  • Enterprise Attestation to support use cases such as derived FIDO credentials
  • FIDO2, PIV and OpenPGP minimum PIN length is now 8
  • PIN complexity is on by default to adhere to NIST Special Publication 800-63B (and 800-63B-4)
  • Larger keys sizes provide better protection than smaller key sizes until Post-Quantum-Cryptography is mature.

5.7 and 5.6 Firmware Prior to 5.7.4

The 5.7 and 5.6 new features include:

  • The NFC function with firmware 5.7 is off by default. Plugging the YubiKey into the device in activates the NFC function. For more detail on this specific feature, see Restricted NFC.
  • The 5.7. firmware for the YubiKey 5 Series has a number of features that are available for the first time on the multi-protocol YubiKey 5.

Firmware Capability Matrices

For form factors released with which firmware versions, see Introduction to the YubiKey Series.

YubiKey 5 Series

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.x 5.5.x 5.4.x 5.3.x 5.2.x 5.0.x
Features
AlwaysUV Yes          
Attestation
Enterprise
Yes          
Blob Storage Yes          
Serial Number Yes Yes Yes Yes Yes Yes
YubiHSM Auth Yes Yes        
FIDO
FIDO U2F Yes Yes Yes Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes Yes Yes Yes
FIDO2 Credential
Storage
100 25 25 25 25 25
FIDO2 PIN Mgmt Yes          
Protocols
OATH Yes Yes Yes Yes Yes Yes
OATH Credential
Storage
64 32 32 32 32 32
OpenPGP version 3.4 3.4 3.4 3.4 2.1 2.1
OTP Yes Yes Yes Yes Yes Yes
PIV/Smart Card Yes Yes Yes Yes Yes Yes
SCP03 Yes Yes Yes      
SCP11 5.7.4+          

YubiKey 5 FIPS Series

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.4 5.4.3 5.4.2
Features
AlwaysUV      
Attestation
Enterprise
     
Blob Storage      
Serial Number Yes Yes Yes
YubiHSM Auth Yes Yes  
FIDO
FIDO U2F Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes
FIDO2 Credential
Storage
100 25 25
FIDO2 PIN Mgmt      
Protocols
OATH Yes Yes Yes
OATH Credential
Storage
     
OpenPGP version 3.4 3.4  
OTP Yes Yes Yes
PIV/Smart Card Yes Yes Yes
SCP03 Yes Yes Yes
SCP11 Yes    

YubiKey 5 Series - Enhanced PIN

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.4
Features
AlwaysUV Yes
Attestation
Enterprise
Yes
Blob Storage Yes
Serial Number Yes
YubiHSM Auth Yes
FIDO
FIDO U2F Yes
FIDO2/WebAuthn Yes
FIDO2 Credential
Storage
100
FIDO2 PIN Mgmt Yes
Protocols
OATH Yes
OATH Credential
Storage
64
OpenPGP version 3.4
OTP Yes
PIV/Smart Card Yes
SCP03 Yes
SCP11 Yes

YubiKey 5 CCN Series

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.4
Features
AlwaysUV Yes
Attestation
Enterprise
Yes
Blob Storage Yes
Serial Number Yes
YubiHSM Auth Yes
FIDO
FIDO U2F Yes
FIDO2/WebAuthn Yes
FIDO2 Credential
Storage
100
FIDO2 PIN Mgmt Yes
Protocols
OATH Yes
OATH Credential
Storage
64
OpenPGP version 3.4
OTP Yes
PIV/Smart Card Yes
SCP03 Yes
SCP11 Yes

YubiKey Bio Series

The listed firmware versions apply to both YubiKey Bio Series and YubiKey Bio Series - Multi-Protocol editions, unless indicated.

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.x 5.6.x 5.5.x
Features
AlwaysUV      
Attestation
Enterprise
     
Blob Storage      
Serial Number Yes Yes Yes
YubiHSM Auth      
FIDO
FIDO U2F Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes
FIDO2 Credential
Storage
100 25 25
FIDO2 PIN Mgmt      
Protocols
OATH Yes Yes Yes
OATH Credential
Storage
     
OpenPGP version 3.4 3.4  
OTP Yes Yes Yes
PIV/Smart Card

Multi-
Protocol
   
SCP03

Multi-
Protocol
Multi-
Protocol
 
SCP11


Multi-
Protocol
5.7.2+
   
SCP03, SCP11, and PIV Support
SCP03, SCP11, and Smart Card/PIV support is only available on the YubiKey Bio Multi-protocol Edition.

Security Key Series

The listed firmware versions apply to both Security Key Series and Security Series Enterprise editions.

Features and Form Factors Available per Firmware Version
Features and
Form Factors

Firmware Versions
5.7.x 5.4.x 5.0.x-5.2.x
Features
AlwaysUV Yes    
Attestation
Enterprise
Enterprise
Edition
   
Blob Storage Yes    
Serial Number
Enterprise
Edition
Enterprise
Edition
 
YubiHSM Auth      
FIDO
FIDO U2F Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes
FIDO2 Credential
Storage
100 25 25
FIDO2 PIN Mgmt Yes    
Protocols
OATH Yes Yes Yes
OATH Credential
Storage
     
OpenPGP version 3.4 3.4  
OTP Yes Yes Yes
PIV/Smart Card
     
SCP03

Enterprise
Edition
   
SCP11


Enterprise
Edition
5.7.4+
   
SCP03, SCP11, Enterprise Attestation, Serial Number Support
SCP03 is only available on the Security Key Series Enterprise Edition.