This documentation is under active development and discussion!

If you find errors or omissions in this document, please don’t hesitate to submit an issue or open a pull request with a fix. We also encourage you to ask questions and discuss any aspects of the project by email.

Figure 1. MemType

Welcome to the MemType documentation, here you’ll learn everything about the MemType hardware, firmware, software tools and usage for any user level.

If you fancy one, you can get it from our tindie store!


Figure 2. MemType top face

Technically speaking the MemType is an open source hardware password keeper. This means it is basically a device focused in securely storing passwords. The open source part means that we share all the software source files, hardware design files and documentation under the License conditions.

Having the passwords stored in a password keeper has several advantages:

  • No reusing same pass in different apps or webs.

  • More secure and long passwords can be used, no need to remember them.

  • No more forgotten passwords.

We like hardware password keepers but we couldn’t find one that satisfied our usability needs, also they were very expensive! That’s why we decided to make the MemType loaded with features and with a reduced BOM that results in a simple low cost device that’s also great for DIY makers and hackers.

MemType features

  • Encrypted storage in the device using NOEKEON written in pure assembler!

  • AES encrypted backups on the PC using the MemTypeTool GUI.

  • Plug it into a USB, no drivers or software for using it.[1]! Works as a HID keyboard.

  • Works anywhere!. While others only work on webs or certain apps, the MemType can be used anywhere from webs, apps, terminals or anywhere it’s allowed to type using a keyboard.

  • One click login. It stores and types for you not only the password but also the user without any interaction from your part, and it also submits it!

  • Add delays to enter the password when it’s asked, for example in ssh or login forms where the user and password are asked in two steps.

  • Dynamic storage. You’re not limited to a certain number of credentials, just fill the 2KB storage with them.

  • Assign names to the credentials so you can find them easy and fast to use them.

  • Manage the device with the MemTypeTool GUI software, super easy and simple!

  • Truly multiplatform. The MemType works on any device with usb keyboard capability like tablets, smart tv, and phones.

  • Any keyboard layout. Load the keyboard layout you’ve got working in your OS using the MemTypeTool GUI.

  • Truly Open Source Software and Hardware.


The data structure used by the MemType to store passwords and usernames is called a credential. Appart from passwords and usernames it also stores a field that stores the key combination to move from the user input to the password input, called hop. It also includes a field for storing the key combination to submit the login form or command, called submit. To help you find the credential you need, each of them has a name stored in the name field.

Field Description


The name that’ll be shown while using the device.


The username of the login.


The sequence of keyboard keys to move from the user input field to the password one. Usually tab, sometimes Enter


The password that’ll be typed into the password input field.


The sequence of keyboard keys to validate the login. Usually Enter.

When a credential is applied, the MemType generates the key sequence like you were typing it into your keyboard, excluding the name by the order of the table above.

In a login form, you focus the username field and then move the MemType joystick up and down looking for the credential you need. When you find the right credential, enter to apply it and the MemType will erase the credential name, type the username, move to the password input field, type it and submit. All this process is done much times faster than any person can type.

There are some cases where you may need a delay in a certain point, for example when the login form asks for the user, validates it and then asks for the password. Such delays can be made by the MemType using one special character when editing the credential. This and more is explained in the Advanced uses section.

It’s easy to see how this credential structure can be used to securely store and type other kind of data like commands or credit card numbers.

When buying online it’s faster and more secure to let the MemType type the credit card number than pulling out the creditcard with the number printed on it.

A way of accomplishing it would be by having all the fields empty except the password field that would contain the credit card number and the name.

N_O_D_E Video review

If you want a great video introduction and review of the MemType, check the following awesome video made by N_O_D_E.

Compare to others password keepers

Quick start

Open a text editor and connect the MemType to the USB port of your computer. You’ll see the red led turning on indicating it’s being powered correctly and it’s locked.

On the text editor it will write a welcome message indicating it’s firmware version:

MemType 3.1.0

You don’t have to delete what it writes, it deletes it’s own text to write new one, that’s how the MemType communicates with you. Now you can unlock it entering the PIN, by default it’s 0000. To enter the PIN use the joystick:

  • up increases the number.

  • down decreases.

  • towards the connector accepts the number.

  • the opposite joystick movement to cancel.

We’ll refer to these movements up, down, enter and back respectively.

You should have now the pin entered:

PIN: 0000

One more enter and it’ll validate and show the name of the first credential and the green led will be on. If the PIN is incorrect an error message will be displayed:


The MemType comes preloaded with 3 dummy credentials so you can play the first time. Move up and down to see their names, apply one with the enter movement on the joystick, see the details with one back movement and lock the device with one more back movement (2 in total) turning the red led on again.

That’s the basic usage of the MemType, now to be useful it has to contain the credentials you’ll use, setup a different PIN, and be loaded with the same keyboard layout as your operating system or you’ll see strange characters. To do all this management on the device there is an easy to use Graphical User Interface software called MemTypeTool GUI.

MemTypeTool GUI

Figure 3. MemTypeTool GUI

The MemTypeTool GUI can be downloaded from :

It is developed using python 2.7 , pyqt4, and libusb so it should work anywhere you can get this dependencies running. It has been tested on Windows, Linux and MacOS.

To run the MemTypeTool:


Windows installation

It has been tested in windows up to 8.1. It has been reported to not work in windows 10.
Using a linux virtual machine can be a workaround for the moment.
  1. Install python 2.7.

  2. Add python to your path:

  3. Download and install PyQt for python 2.7.

  4. Download, unzip and install libusb:

  5. Plug in the Memtype and let windows install the drivers for the device (we’ll change them in the next step).

  6. Download and extract libusb-win32:

  7. Execute install-filter-win (find it inside extracted folder, under /bin/x86 or other if your windows is 64bits).

    1. Select Install Filter, next.

Filter step 1
Figure 4. Windows libusb filter, step 1
  1. Select Memtype (pid a033) and click Install

Filter step 2
Figure 5. Windows libusb filter, step 2
  1. Done!!! you can check it with the testlibusb-win found next to install-filter-win:

Test filter windows
Figure 6. Check windows filter

Linux installation

Example ubuntu installation steps:

apt-get install python
apt-get install python-pyqt4
pip install pyusb

MacOS installation


You can use the bottom input text to communicate with your memtype, focusing it with a mouse click if it’s not already focused.

Setting the keyboard layout

Using the GUI you can change the MemType keyboard layout to match your computer keyboard layout. The current available layouts files are located under keyboard directory.

Setting the P.I.N.

Changing the default PIN is a very important action that should be done as soon as possible before loading any credential into de MemType.

Reading from device

You can read the credentials from the MemType to do any action to them and write them back, or make an encrypted file backup by Exporting encrypted file.

Writting to device

When you’ve got everything looking OK in the MemTypeTool GUI you have to write the credentials to the MemType device so you can use them.

Another option would be to simply store them by Exporting encrypted file.

Adding credentials

Adding credentials is easy, when you’ve got your new credentials created remember Writting to device.

Editing credentials

Editing is essential, edit to have your passwords in the credentials, usernames and any other field so you can forget them!

Deleting credentials

Delete by clicking into the bin icon of any credential. The changes will not take effect until you write to the device.

Exporting encrypted file

You can have backups in your computer, or have one AES encrypted file containing all the credentials for a given user role in your company.

Don’t forget the file password or there’ll be no way of getting back the credentials from that file.

Importing from encrypted file

As easy as exporting, enter the file password and your credentials will be ready to be edited.

Adding delays to credentials

Using the MemType

P.I.N. Unlock

Use a credential

Credential details

Lock the device

Advanced uses

MemType library

The MemType library (libsmttool) is a python library that allows communication with the MemType in python. It allows all the operations that can be realized with the MemTypeTool GUI as it’s based on libsmttool.

It also can be found under the libsmttool directory when downloading the MemTypeTool GUI.

It’s composed of two modules, the file and the file.

This library depends on:

  • python2.7

  • libusb-1.0-0

  • pyusb

As the memtype uses internally the noekeon algorithm for encrypting the credentials, this algorithm has to be used in the MemTypeTool GUI to decrypt them back.

This file provides a python implementation based on the noekeon specification.

NOEKEON is an iterated block cipher with a block and key length of 128 bits.

The public methods implemented in the library are:

  1. NoekeonEncrypt(WorkingKey, State)

  2. NoekeonDecrypt(WorkingKey, State)

The Number of Rounds is defined by NUMBER_OF_ROUNDS and fixed to 16.

WorkingKey format is 4 elements of 32 bit length each.

State is the information to be encrypted / decrypted in 4 elements of 32 bit.

MemType command library implementation.

Public methods implemented in file:

  1. memtype Class Communicates with the device.

    1. connect Open USB connection with device.

    2. disconnect Close USB connection with device.

    3. info Read info from device and return deviceInfo object.

    4. write Write credentials to memtype credential reserved memory area, credential data must be encrypted with the right PIN.

    5. read Read credentials from memtype, must be decrypted with the right PIN.

    6. writePinHash Writes PIN hash into memtype, pinToHas function can be used to generate the hash.

    7. readPinHash Reads the PIN hash from the memtype.

    8. writeKeyboardLayout Writes a keyboard layout into the memtype device.

    9. isLocked Returns TRUE if the memtype has not been unlocked with PIN.

    10. validatePin When the memtype is unlocked, checks if a PIN corresponds to the PIN hash and returns TRUE, FALSE otherwise.

  2. decryptCredentialList(cl, key) Decrypts a credential list according to device implementation.

  3. encryptCredentialList(cl, key) Encrypts a credential list according to device implementation.







  1. Can I make a MemType myself?

    Yes! It’s a great DIY project!. You can make your PCB using the design files or order one from OSHpark, buy the components, solder them, compile the firmware and burn it into the microcontroller!

  2. How many credentials can be stored?

    The capacity of the credentials storage on the MemType is 2KB. Credentials are stored dinammically so it’ll depend on the length of the name, username, password etc…​

  3. Can I make a backup of my credentials?

    Having a backup of the credentials is always a good idea. You can export an encrypted file from the MemTypeGUI containning all your credentials.

1. Using it doesn’t require software or drivers. For managing operations like storing credentials or changing the PIN the MemTypeTool is needed and depending on the OS the libusb driver.