Frequently Asked Questions (FAQ)

  • General

    General product-specific questions and answers.

    • Can I backup the internal keys?

      It depends. No one can copy the keys which are stored on the Nitrokey. But depending on the key creation process you can still have a backup of the keys.

      If you use Thunderbird's or GnuPG's function for generating keys directly on-card, it will propose you a backup. But this is a backup of the encryption subkey only! That is to say it is not a full key backup. Restoring this backup leaves you unable to sign or authenticate. Therefore it is not recommend to even create this backup. Technically the subkey is generated on your computer, backed-up, and then loaded to the Nitrokey so that it cannot get copied afterwards. By using this option you have not a full functional backup, but still expose the encryption key on your machine instead of creating the key directly on the device.

      If you need and want a backup of your key, you have to create the keys locally first (ideally on a safe Live-System), so that you can backup them and move the keys on the Nitrokey afterwards. Please have a look at this instructions for further information.

    • What can I use the Nitrokey for?

      See the frontpage for an overview of supported use cases.

    • Which operating systems and applications are supported?

      Supported operating systems: Windows, Linux, and Mac OS X.

      Supported applications: See the documentation.

    • How large is the storage capacity?

      Nitrokey Pro, Nitrokey Start, Nitrokey HSM and Nitrokey U2F don't contain storage capability for ordinary data (it can only store cryptographic keys and certificates).

      Nitrokey Storage can store and encrypt 8, 32, or 64 GB of data (depending on particular model).

    • What is the default PIN/password?

      • User PIN: "123456"
      • Administrator PIN: "12345678"
      • Firmware Password (Nitrokey Storage only): "12345678"
      • SO-PIN (Nitrokey HSM only): "3537363231383830"

      We strongly recommend to change these PINs/password to user-chosen values before using the Nitrokey.

    • What is the maximum length of the PIN?

      Nitrokey uses PINs instead of passwords. The main difference is that the hardware limits the amount of tries to three while a limit doesn't exist for passwords. Because of this, a short PIN is still secure and there is not need to choose a long and complex PIN.

      Nitrokey Pro's and Storage's PINs can be up to 20 digits long and can consist of numbers, characters and special characters. Note: When using GnuPG or OpenSC, 32 character long PINs can be used but aren't supported by Nitrokey App.

    • What is user/admin/firmware PIN/password for?

      User PIN

      The user PIN is at least 6-digits long and is used to get access to the contect of the Nitrokey. This is the PIN you will use a lot in every day use e.g. for decrypting messages, for unlocking your encrypted storage (NK Storage only) etc.

      The user PIN can have up to 20 digits and other characters (e.g. alphabetic and special characters). But as the user PIN is blocked as soon three wrong PIN attempts were done, it is sufficiently secure to only have a 6 digits PIN. The default PIN is 123456.

      Admin PIN

      The admin PIN is at least 8-digits long and is used to change contents/settings of the Nitrokey. That is to say after initializing the Nitrokey you probably won't need this PIN too often (e.g. if you want to add another password to the password safe of the Nitrokey Pro or Nitrokey Storage).

      The admin PIN can have up to 20 digits and other characters (e.g. alphabetic and special characters). But as the admin PIN is blocked as soon three wrong PIN attempts were done, it is sufficiently secure to only have 8 digits PIN. The default PIN is 12345678.

      Firmware password

      The firmware password should meet general password recommandations (e.g. use alphabetic characters, digits and special characters or use a usfficiently long password). The firmware password is needed to update the firmware of the Nitrokey Storage. See further instructions for update process here.

      The firmware password is never blocked. An attacker could try to guess the password and would have unlimited attempts. Therefore you must choose a strong password. The default password is 12345678.

      SO PIN

      The SO PIN is used in the Nitrokey HSM only and is something like a "master" PIN with special properties. Please read this instructions carefully to understand the SO PIN of the Nitrokey HSM.

    • How many keys can I store?

      The Nitrokey Pro, Nitrokey Start and Nitrokey Storage can store three RSA key pairs. All keys use the same identity but are used for different purposes: authentication, encryption and signing.

      Nitrokey HSM can store 20 RSA-2048 and 31 ECC-256 key pairs.

      Nitrokey U2F stores a single ECC key pair but can be used with an unlimited amount of user accounts.

    • Which algorithms and maximum key length are supported?

      • Nitrokey Pro: RSA 1024-4096 bit. It can store one X.509 certificate with a size of up to 2 KB.
      • Nitrokey Storage: RSA 1024-4096 bit. Mass storage: AES-256 bit
      • Nitrokey Start: RSA 2048 bit, brainpoolP256r1, secp256k1 (the Bitcoin curve) and NIST P-256 (see this post).
      • Nitrokey HSM: RSA 1024-2048 bit, ECDSA GF(p) 192-320 bit, elliptic curves:
        • secp192r1 (aka prime192v1)
        • secp256r1 (aka prime256v1)
        • brainpoolP192r1
        • brainpoolP224r1
        • brainpoolP256r1
        • brainpoolP320r1
        • secp192k1
        • secp256k1 (the Bitcoin curve)
      • Nitrokey U2F: ECC 256 bit (NIST P-256) as required by the FIDO U2F specification.

      As part of hybrid encryption, additional symmetric encryption (e.g. AES) is performed on the computer and only the session key is send to the Nitrokey (to be decrypted with RSA). This is a standard mechanism and allows optimal performance even for large amounts of data.

    • Wieviele Datenobjekte (DF, EF) können gespeichert werden?

      Nitrokey HSM:

      Die Anzahl der Datenobjekte (DF, EF) ist auf 124 beschränkt. Die maximale Größe eines EF beträgt 256 Byte. Der maximale Speicher von ca. 32 KByte wird dynamisch zwischen Schlüssel- und Datenobjekten geteilt.

    • How fast is encryption and signing?

      In general the encryption and decryption of emails, hard disks and any other type of (large) data with the Nitrokey has almost no performance reduction. This is because of hybrid encryption approach. It means that AES for example is used to encrypt gigabytes of data at the computer and only the session key is send to the Nitrokey to be decrypted with RSA.

      Nitrokey HSM:

      • Key generation on-card: RSA 2048: 2 per minute
      • Key generation on-card: ECC 256: 10 per minute.
      • Signature creation with off-card hash: RSA 2048; 100 per minute
      • Signature creation with off-card hash: ECDSA 256: 360 per minute
      • Signature creation with on-card SHA-256 and 1 kb data: RSA 2048; 68 per minute
      • Signature creation with on-card SHA-256 and 1 kb data: ECDSA 256: 125 per minute

      Nitrokey Storage's mass storage: Storing files on the encrypted mass storage is 5-6 MByte/s fast (both read/write).

      Nitrokey Pro and Storage (v1)

      Internal performance for a single 16 byte block without input/output to the smart card:

      • 100 decryptions: AES 128: 169 milliseconds
      • 100 decryptions: AES 192: 162 milliseconds
      • 100 decryptions: AES 256: 170 milliseconds
      • 100 encryptions: AES 128: 147 milliseconds
      • 100 encryptions: AES 192: 158 milliseconds
      • 100 encryptions: AES 256: 168 milliseconds

      Nitrokey Pro and Storage (v2)

      Encryption of 50kiB of data:

      • 256 bit AES, 2048 bytes per command -> 880 bytes per second
      • 128 bit AES, 2048 bytes per command -> 893 bytes per second
      • 256 bit AES, 240 bytes per command -> 910 bytes per second
      • 128 bit AES, 240 bytes per command -> 930 bytes per second
    • Do Nitrokeys contain a secure chip or just a normal microcontroller?

      Nitrokey Pro, Nitrokey HSM and Nitrokey Storage contain a tamper resistant smart card. To some extent this also applies to Nitrokey U2F but it's of lower quality. Nitrokey Start is implemented in the microprocessor.

    • How good is the Random Number Generator (RNG)?

      Nitrokey Pro and Nitrokey Storage:

      Nitrokey Pro and Nitrokey Storage use a True Random Number Generator (TRNG) for generating keys on the device. The entropy generated by the TRNG is used for the entire key length. Therefore the TRNG is compliant to BSI TR-03116.

      The TRNG provides about 40 kbit/s.

      Nitrokey HSM:

      Nitrokey HSM uses the TRNG of JCOP 2.4.1r3 which has a quality of DRNG.2 (according to AIS 31 of the BSI).


      Please see here.

    • Is Nitrokey Common Criteria or FIPS certified?

      Nitrokey's products as a whole aren't Common Criteria or FIPS certified but are available as Open Source for own evaluations.

      Nitrokey Storage (1 and 2)

      Cure53 has performed an independent security audit of the Nitrokey Storage's hardware, firmware, and Nitrokey App.

      The security controler's hardware is Common Criteria certified (Report; See here, click "ICs, Smart Cards and Smart Card-Related Devices and Systems" and search for "NXP Smart Card Controller P5CD081V1A and its major configurations P5CC081V1A, P5CN081V1A, P5CD041V1A, P5CD021V1A and P5CD016V1A each with IC dedicated Software").

      Nitrokey Pro (1 and 2)

      The security controler's hardware is Common Criteria certified (Report; See here, click "ICs, Smart Cards and Smart Card-Related Devices and Systems" and search for "NXP Smart Card Controller P5CD081V1A and its major configurations P5CC081V1A, P5CN081V1A, P5CD041V1A, P5CD021V1A and P5CD016V1A each with IC dedicated Software").

      Nitrokey HSM

      The security controler's hardware and operating system are Common Criteria certified (Report; See here, click "ICs, Smart Cards and Smart Card-Related Devices and Systems" and search for "NXP J3A080 v2.4.1 Secure Smart Card Controller (JCOP v2.4.1)").

  • Usage and Troubleshooting

    Usage-specific questions and answers.

    • "OpenPGP Karte ist nicht vorhanden"


      Folgender Fehler tritt unter Umständen auf Ihrem GNU/Linux System auf:

      $ gpg --card-status ODER $ gpg --card-edit
      gpg: selecting openpgp failed: unknown command
      gpg: OpenPGP Karte ist nicht vorhanden: general error

      Es gibt verschiedene mögliche Gründe für diesen Fehler. Falls Sie den Nitrokey gerade erst einrichten und vorher nie benutzt haben, schauen Sie unter dem Bereich "UDEV Regeln" weiter unten. Wenn Sie das Gerät bereits einige Male verwendet haben, blockiert vermutlich eine andere Anwendung den Nitrokey, indem die Software die OpenPGP Card exklusiv nutzt. Schaue Sie sich zum Beheben dieses Problem die weiteren Hinweise unten an. Es kann auch helfen, den Nitrokey schlicht einmal ein- und auszustecken.

      Fehlende UDEV Regeln

      Der einfachste Weg, dieses Problem zu beheben, ist das Installieren der Nitrokey App. Ab der Nitrokey App version 1.2, sollten Sie keine Probleme mit den UDEV Regeln haben.

      Wenn Sie die Regeln lieber händisch installieren wollen, führen Sie bitte folgende Befehle aus:

      sudo mv 41-nitrokey.rules /etc/udev/rules.d/


      Falls der Gnome-Keyring die OpenPGP Card blockiert, sollte der folgende Befehl das Problem für die aktuelle Sitzung beheben: pkill -f gnome-keyring-daemon.
      Für eine dauerhafte Lösung das Problems, schauen Sie sich bitte diesen und diesen Beitrag an (Englisch).

      Andere Anwendungen

      Have look at applications you installed for use with the Nitrokey and check if they may are blocking the Nitrokey. For example OpenSC can make your Nitrokey stop working. After finding out what program provokes this kind of behaviour you are maybe able to fix the problem. You can ask for help in the forum as well.

      Mac OS

      1. Remove your Nitrokey
      2. Execute in the terminal sudo mv /System/Library/Security/tokend/OpenSC.tokend ~/Desktop

      Now, plug in your Nitrokey and use it with GnuPG.

      To undo the change in order to use it with OpenSC:

      1. Remove your Nitrokey
      2. Execute in the terminal sudo mv ~/Desktop/OpenSC.tokend /System/Library/Security/tokend/
    • How to troubleshoot?

      Troubleshooting related to GnuPG

      1. Connect your Nitrokey to your computer and verify if the device is recognized correctly and the driver is loaded. The LED of the stick should flash for a moment and than stop shining.
        • Linux: $ tail -v /var/log/syslog

        • Mac OS: $ tail -f /var/log/system.log

        • Windows: Start -> Preferences -> Control Panel -> System -> Hardware -> Device Manager -> Smart card adapter

      2. Check if GnuPG recognizes the device: gpg --card-status resp. gpg2 --card-status (depending on the version) should deliver some status information of the Nitrokey.

      3. If both GnuPG version 1 and version 2 are installed, verify if your email application uses the correct version of GnuPG. You may modify it in the appropriate preferences.
      4. Verify to use a current version of GnuPG, at least 1.4.10 resp 2.0.18.

      5. Try using GnuPG 1 instead of GnuPG 2.

      6. Remove the packages openct and opensc because they may interfere with GnuPG.

      7. Use 2048 bit keys instead of 3072 or 4096 bit keys.

      8. Test the Nitrokey on another computer or with another operating system.

      9. Reset the device and delete all keys.

      10. Add the following lines to ~/.gnupg/scdaemon.conf and provide the resulting log file for debugging purposes, where <username> is the name of your user account.
        debug 2048
        log-file /home/<username>/scdaemonlog.txt

      Troubleshooting related to OpenSC with Nitrokey HSM

      1. Set the environment variable OPENSC_DEBUG=9 or configure it in opensc.conf
      2. Provide OpenSC's log file.
    • Nitrokey Storage doesn't work anymore under Windows after upgrading the firmware

      1. Use this tool to delete all entries with USB Devices ProductID 4109 and VendorID 20A0 in the registry.
      2. Reset the Nitrokey device.
      3. Install and use the latest App.
    • On my MacOS keyboard the keys < and ^ are swapped

      Delete the file /Library/Preferences/ and restart your computer.

    • How to reset a Nitrokey?

      Warning: When resetting the Nitrokey all information on the device get lost! If you have multiple devices or other smart card reader please make sure only the one you want to reset is connected!

      Nitrokey Pro and Nitrokey Storage:

      Option 1, if the device is not fully blocked and if you remember the valid Admin PIN use Nitrokey App to reset the Nitrokey.

      Open a terminal (for example on Windows: press the Start button and enter "cmd") and start the Nitrokey App with "nitrokey-app --admin". Klick on the Nitrokey App's tray icon, select "Configure" and "Factory reset".

      Option 2, Windows only:

      Use CryptoStickReset.

      Option 3, to reset a blocked device with GnuPG 2 and Windows:

      1. Download and install Gpg4win.
      2. Download and execute this reset script.

      Option 4, to reset a blocked device with GnuPG 2 and Linux:

      1. Download this file
      2. Open a command prompt (terminal) and run "gpg-connect-agent < nitrokey-reset.txt".
        In case of error  "ERR 67108983 No SmartCard daemon <GPG Agent>" please install scdaemon (e.g. "sudo apt install scdaemon").

      Option 5, to reset a blocked device with GnuPG 2.1:

      1. Ensure that you use GnuPG 2.1: "gpg --version"
      2. Reset device: "gpg2 --card-edit" -> "admin" -> "factory-reset"

      Option 6, to reset a blocked device using OpenSC:

      Install OpenSC and execute "openpgp-tool --erase" in a terminal.

      Nitrokey Start:

      You can find out the version of your device by executing gpg --card-status (the version number is behind 'FSIJ' in the 'Reader' field). To upgrade your device see this instructions (admin PIN needed!).

      Nitrokey Start firmware 1.2.6 and newer:

      1. Ensure that you use GnuPG 2.1 or higher: "gpg --version"
      2. Reset device: "gpg2 --card-edit" -> "admin" -> "factory-reset"

      Nitrokey Start firmware 1.2.2 to 1.2.4:

      If and only if the device is not blocked (PIN wasn't typed in wrong too often) you can use the same procedure as in newer firmware (see above). You need the reset code to unblock device or you can not use the device anymore!

      Nitrokey Start firmware 1.0:

      In order to reset a Nitrokey Start 1.0, you need to define a public key for firmware updates beforehand! In case of a blocked device it enables your to perform a firmware update which resets the device.

      You may also define a reset code which enables the reset of the User PIN (not Admin PIN).

      Nitrokey HSM:

      As long as you know the unblocked SO-PIN you can initialize the device as described here. There is no way of resetting the Nitrokey HSM if the SO-PIN is forgotten or entered wrongly 15 times. In such case the device can't be used anymore.

    • How to use the Nitrokey with multiple computers?

      Prerequisite: An initialized Nitrokey with keys being generated.

      On another computer, than the one you generated the keys on, you need to inform GnuPG about the Nitrokey. You have two options for doing so:

      If you published your public key on your website you should program that URL into your smartcard in the "URL of public key" section (gpg --card-edit, admin, url). In addition or instead you may want to publish your public key on a key server. When you get to a new computer, you can insert the card, run "gpg --card-edit", then run "fetch" and GPG will fetch the public key from the URL. If there's no URL entered then it will attempt to retrieve the public key from the keyserver.

      Alternatively, you can copy and import the public key manually from a flash drive for instance. In this case you have to insert the device and run "gpg --card-status". (Now the general key info will be correctly populated, and new pseudo-secret stubs will be created.)

      In any case the keyring file (e.g. ~/.gnupg/pubring.gpg) which contains the public keys of your contacts has to be copied manually.

      See this more detailed description.

    • How to update the firmware of Nitrokey Storage?

      See these instructions.

    • How to update the firmware of Nitrokey Start?

      See these instructions (on GitHub).

    • Ubuntu: Tray icon is displayed at the wrong corner of the screen

      Execute the following commands in a terminal.

      $ sudo apt-add-repository ppa:gurqn/systray-utopic
      $ sudo apt-get update
      $ sudo apt-get upgrade

      Logout and login again to your computer account.

    • Key generation fails with Nitrokey Start

      Nitrokey Start doesn't support overriding keys in firmware version prior to 1.2 (see 'gpg --card-status', the number after "FSIJ-" is the firmware version). Once keys were generated or written, you should use the Python script to remove keys.

      On firmware versions higher or equal 1.2 you can override the keys. But please note that your PIN gets reset with factory defaults when overriding the keys!

    • How to make GnuPG release exclusive smartcard access?

      GnuPG blocks the smart card so that other applications can't access it in "parallel" (within several minutes or within the same user session).


      1. This gives up on the card immediately:
      "gpgconf --kill scdaemon"
      On Unix you may also execute "pkill scdaemon".
      2. This delays the smart card release until all scdaemon clients have sent a disconnect:
      Put "card-timeout 1" int scdaemon.conf and run "gpg-connect-agent disconnect /bye" if you do not need the OpenPGP card anymore.
      3. Patch GnuPG itself and recompile:



        err = pcsc_connect (reader_table[slot].pcsc.context,


        err = pcsc_connect (reader_table[slot].pcsc.context,


      • GPG1.4: Once in g10/apdu.c:1278
      • GPG2.0: Once in scd/apdu.c and twice in scd/pcsc-wrapper.c
      • GPG2.1: Once in scd/apdu.c
    • Which GnuPG, OpenSC and libccid versions are required?

      GnuPG 2.0.18 or newer. We recommend the 2.0 main version. 2.1 is still a bit unstable in our experience.

      OpenSC 0.16 or newer. Version 0.15 is not sufficient and you would need its nightly builds or compile it from their git repository.

      libccid 1.4.22 or newer.

    • How to use Nitrokey with VMware or other virtualization systems?

      Nitrokey Pro and Nitrokey Storage expose a USB Human Interface Device (HID) which some virtualization systems don't pass to the guest systems by default. Hence the VM needs to be configured appropriately. How to do this for VMware is described here.

    • Neueste Gerätetreiber fehlen auf alter Linux Distribution

      Dieser Schritt ist nur notwendig falls das Linux System nicht die neuesten Geräte Treiber hat (ccid Version < 1.4.21). Bearbeiten Sie die Datei /etc/libccid_Info.plist (zum Beispiel indem Sie "sudo gedit /etc/libccid_Info.plist" in die Konsole eingeben) und fügen Sie die folgenden fett gedruckten Zeilen hinzu:

            <string>Nitrokey Pro</string>
            <string>Nitrokey Storage</string>
            <string>Nitrokey Start</string>
            <string>Nitrokey HSM</string>
  • Shop and Delivery

    • Wie lange dauert der Versand?

      Brief und Einschreiben:

      • Deutschland: 2-5 Arbeitstage
      • EU: 5-10 Arbeitstage
      • Weltweit: 2-3 Wochen


      • Deutschland: 1-3 Arbeitstage
      • EU: 2-5 Arbeitstage
      • Weltweit: 5-10 Arbeitstage
    • Preise und Umsatzsteuer/Mehrwertsteuer

      Die Nitrokey UG besitzt einen heterogenen Kundenstamm, aus Privat- und Geschäftskunden, aus Deutschland, der EU und dem außereuropäischen Ausland. Wir wollen mit unserer Preisgestaltung sicherstellen, dass alle Kunden eine einheitliche Belastung haben. Zum Beispiel soll ein großer internationaler Konzern genau soviel zahlen wie eine deutsche Privatperson. Deshalb entspricht der Bruttopreis (inkl. USt.) für deutsche Kunden dem Nettopreis (exkl. USt.) außereuropäischer Kunden. Dieser Ansatz wurde steuerrechtlich überprüft und ist einwandfrei.

    • How is the Bitcoin exchange rate calculated?

      At the time of ordering, our system takes the exchange rate from and adds 10% on top of it. The 10% are for our handling fees (exchanging Bitcoins back to Euro) and for the risk implicated by floating exchange rate.

  • Development