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
Factor

YubiKey
Form
Name
Firmware Versions
5.8 5.7.x 5.5.x 5.4.x 5.3.x 5.2.x 5.0.x
USB-A + NFC 5 NFC Yes Yes Yes Yes Yes Yes Yes
USB-C + NFC 5C NFC Yes Yes Yes Yes Yes Yes  
USB-A Nano 5 Nano Yes Yes Yes Yes Yes Yes Yes
USB-C Nano 5C Nano Yes Yes Yes Yes Yes Yes Yes
USB-A + bio sensor 5 Bio Yes Yes Yes        
USB-C + bio sensor 5C Bio Yes Yes Yes        
USB-C + Lightning 5Ci Yes 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 Matrices.

5.8 Firmware - FIDO2 and CTAP 2.3

The 5.8. firmware for the YubiKey 5 Series has a number of features that are available for the first time on the YubiKey 5. The changes and additions are described in detail in 5.8 Firmware Specifics. In addition to the features that are directly accessible, there are a number of features that require partner support.

5.7.4 Firmware - FIPS Series

The 5.7.4 new features include:

  • Certified 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 Available per Firmware Version

Features

Firmware Versions
5.8.x 5.7.x 5.5.x 5.4.x 5.3.x 5.2.x 5.0.x
AlwaysUV Yes Yes          
Attestation
Enterprise
Yes Yes          
Blob Storage Yes Yes          
Serial Number Yes Yes Yes Yes Yes Yes Yes
YubiHSM Auth Yes Yes Yes        
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
Yes            
Pseudo-Random (PRF) Yes            
Reset LongTouch Yes            
Reset Transport Yes            
Third Party Payment Yes            
FIDO
FIDO2 CTAP 2.3 Yes            
FIDO U2F Yes Yes Yes Yes Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes Yes Yes Yes Yes
FIDO2 Credential
Storage
100 100 25 25 25 25 25
FIDO2 PIN Mgmt Yes Yes          
FIDO2 over CCID Yes            
Protocols
OATH Yes Yes Yes Yes Yes Yes Yes
OATH Credential
Storage
64 64 32 32 32 32 32
OpenPGP version 3.4 3.4 3.4 3.4 3.4 2.1 2.1
OTP Yes Yes Yes Yes Yes Yes Yes
PIV/Smart Card Yes Yes Yes Yes Yes Yes Yes
SCP03 Yes Yes Yes Yes      
SCP11 Yes 5.7.4+          

YubiKey 5 FIPS Series

Features and Form Factors Available per Firmware Version

Features

Firmware Versions
5.7.4 5.4.3 5.4.2
AlwaysUV      
Attestation
Enterprise
     
Blob Storage      
Serial Number Yes Yes Yes
YubiHSM Auth Yes Yes Yes
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
Yes    
Pseudo-Random (PRF)      
Reset LongTouch      
Reset Transport      
Third Party Payment      
FIDO
FIDO2 CTAP 2.3      
FIDO U2F Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes
FIDO2 Credential
Storage
100 100 25
FIDO2 PIN Mgmt      
FIDO2 over CCID Yes    
Protocols
OATH Yes Yes Yes
OATH Credential
Storage
     
OpenPGP version 3.4 3.4 3.4
OTP Yes Yes Yes
PIV/Smart Card Yes Yes Yes
SCP03 Yes Yes Yes
SCP11 Yes    

Note

YubiKey FIPS series remains on firmware version 5.7.4 while FIPS certification for firmware 5.8 is processing.

YubiKey 5 Series - Enhanced PIN

YubiKey 5 Enhanced PIN Series requires a subscription to YubiKey as a Service. Contact Yubico sales team for information about YubiKey as a Service.

Features and Form Factors Available per Firmware Version

Features

Firmware Versions
5.8.x 5.7.4
AlwaysUV Yes Yes
Attestation
Enterprise
Yes Yes
Blob Storage Yes Yes
Serial Number Yes Yes
YubiHSM Auth Yes Yes
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
Yes  
Pseudo-Random (PRF) Yes  
Reset LongTouch Yes  
Reset Transport Yes  
Third Party Payment Yes  
FIDO
FIDO2 CTAP 2.3 Yes  
FIDO U2F Yes Yes
FIDO2/WebAuthn Yes Yes
FIDO2 Credential
Storage
100 100
FIDO2 PIN Mgmt Yes Yes
FIDO2 over CCID Yes  
Protocols
OATH Yes Yes
OATH Credential
Storage
64 64
OpenPGP version 3.4 3.4
OTP Yes Yes
PIV/Smart Card Yes Yes
SCP03 Yes Yes
SCP11 Yes Yes

YubiKey 5 CCN Series

Features and Form Factors Available per Firmware Version

Features

Firmware Versions
5.8.x 5.7.4
AlwaysUV Yes Yes
Attestation
Enterprise
Yes Yes
Blob Storage Yes Yes
Serial Number Yes Yes
YubiHSM Auth Yes Yes
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
   
Pseudo-Random (PRF)    
Reset LongTouch    
Reset Transport    
Third Party Payment    
FIDO
FIDO2 CTAP 2.3    
FIDO U2F Yes Yes
FIDO2/WebAuthn Yes Yes
FIDO2 Credential
Storage
100 100
FIDO2 PIN Mgmt Yes Yes
FIDO2 over CCID    
Protocols
OATH Yes Yes
OATH Credential
Storage
64 64
OpenPGP version 3.4 3.4
OTP Yes Yes
PIV/Smart Card Yes Yes
SCP03 Yes Yes
SCP11 Yes Yes

YubiKey Bio Series

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

Yubico Bio Series - Multi-Protocol Edition requires a subscription to YubiKey as a Service. Contact Yubico sales team for information about YubiKey as a Service.

Features and Form Factors Available per Firmware Version

Features

Firmware Versions
5.8.x 5.7.x 5.6.x 5.5.x
AlwaysUV Yes      
Attestation
Enterprise
Yes      
Blob Storage Yes      
Serial Number Yes Yes Yes Yes
YubiHSM Auth Yes      
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
Yes      
Pseudo-Random (PRF) Yes      
Reset LongTouch Yes      
Reset Transport Yes      
Third Party Payment Yes      
FIDO
FIDO2 CTAP 2.3 Yes      
FIDO U2F Yes Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes Yes
FIDO2 Credential
Storage
100 100 25 25
FIDO2 PIN Mgmt Yes      
FIDO2 over CCID Yes      
Protocols
OATH Yes Yes Yes Yes
OATH Credential
Storage
Yes      
OpenPGP version 3.4 3.4 3.4  
OTP Yes Yes Yes Yes
PIV/Smart Card
Multi-
Protocol
Multi-
Protocol
   
SCP03
Multi-
Protocol
Multi-
Protocol
Multi-
Protocol
 
SCP11
Multi-
Protocol

Multi-
Protocol
5.7.2+
   

Security Key Series

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

Security Key Series - Enterprise Edition requires a subscription to YubiKey as a Service. Contact Yubico sales team for information about YubiKey as a Service.

Features and Form Factors Available per Firmware Version

Features

Firmware Versions
5.8 5.7.x 5.4.x 5.0.x-5.2.x
AlwaysUV Yes Yes    
Attestation
Enterprise
Enterprise
Edition
Enterprise
Edition
   
Blob Storage Yes Yes    
Serial Number
Enterprise
Edition
Enterprise
Edition
Enterprise
Edition
 
YubiHSM Auth Yes      
CTAP
CTAP 2.3 Conditional
Mediation,
PPUAT, PCMR
Yes      
Pseudo-Random (PRF) Yes      
Reset LongTouch Yes      
Reset Transport Yes      
Third Party Payment Yes      
FIDO
FIDO2 CTAP 2.3 Yes      
FIDO U2F Yes Yes Yes Yes
FIDO2/WebAuthn Yes Yes Yes Yes
FIDO2 Credential
Storage
100 100 25 25
FIDO2 PIN Mgmt Yes Yes    
FIDO2 over CCID Yes      
Protocols
OATH Yes Yes Yes Yes
OATH Credential
Storage
Yes      
OpenPGP version 3.4 3.4 3.4  
OTP Yes Yes Yes Yes
PIV/Smart Card Yes      
SCP03
Enterprise
Edition
Enterprise
Edition
   
SCP11
Enterprise
Edition

Enterprise
Edition
5.7.4+
   

SCP03, SCP11, Enterprise Attestation, and Serial Number Support are only available on the Security Key Series Enterprise Edition.