- Can A Virtual Hsm Generate Dukpt Keys 2017
- Can A Virtual Hsm Generate Dukpt Keys On Iphone
- Can A Virtual Hsm Generate Dukpt Keys Download
Dukpt.NET is a C# implementation of the Derived Unique Key Per Transaction (DUKPT) process that's described in Annex A of ANS X9.24-2004.
It is used most of the systems by default. Windows server 2012 ssh server. $ ssh-keygen -b 4096 Generate 4098 Bit Key Generate 4096 Bit DSA KeyRSA is very old and popular asymmetric encryption algorithm. We will use -b option in order to specify bit size to the ssh-keygen.
To install Dukpt.NET, run the following command in the Package Manager Console:
Essentially, one Base Derivation Key (BDK) is used to initiate the DUKPT process. The BDK itself is never exposed, but instead is used to create another key, called an initial key. This initial key is injected into the new POS device along with a Key Serial Number containing identifying information for.
Usage
Overview
It's no secret that Annex A is hard to understand, and the entire process isn't explained in a manner that's easy to follow or translate into code. One of the reasons it's difficult to understand is that it was written from the perspective of an electrical/computer engineer that would directly implement these instruction on the devices/swipers themselves, and as a result it mentions various registers and operations that most of us don't have much experience with. So it's not necessarily for high-level software developers looking to use the process either for new software, backwards compatibility with existing technology, or logging/testing purposes.
- Virtual Keys and Virtual Character Keys. With ordinary rules, you can match any key that produces a character. However, sometimes you may want to match other keys, for example Backspace, or Ctrl- or Alt-combinations. In order to match keys like these you need to use virtual keys. Every key on the keyboard is identified by a virtual key code.
- Derived keys keep information safe. The process cannot be reversed to lead back to the BDK, and if one of the keys were compromised in a POS device, it would immediately be replaced by a new key in the next transaction. Through derivation, DUKPT forms a self-recycling system that promotes security, efficiency, and ease of implementation.
- If you continue this process for a long time you will see it derives a key for every 21-bit binary value other than zero, of which there are 2097151; but DUKPT prescribes that counter values with more than 10 bits set are skipped, so only 1048575 of these values, and their corresponding keys, are used - and as I said in the summary above, that.
I wrote this implementation of DUKPT for fun. This library only has about 100 lines of code and only focuses on DUKPT encryption and decryption.
It still amazes me how scarcely documented this process is, even though it seems like a fairly standard practice. Unfortunately, the advice people usually receive it to purchase the spec for $140.
Key Management
I'm sure you can find a more extensive overview of this process somewhere else, but here's a basic outline of the technique:
- You're given a Base Derivation Key (BDK), which you assign to a swiper (note that the same BDK can be assigned to multiple swipers).
- You'll use the BDK along with the device's own unique Key Serial Number (KSN) to generate an Initial PIN Encryption Key (IPEK) for the device.
- You'll assign this IPEK to a swiper, which uses it to irreversibly generate a list of future keys, which it'll use to encrypt its messages.
- The swiper's KSN is used along with one of its future keys to encrypt a message, and after each swipe it'll increment the value of its KSN.
- Whenever a swiper takes a card it formats the card's information into a series of tracks, each track having a particular set of information (e.g. card number, holder's name, expiration date).
- The swiper usually encrypts these tracks using one of its generated future keys (called the 'Session Key') along with its current KSN. It'll then increment the value of its KSN and discard the future key it used.
- At this point you'll probably have an encrypted track along with the KSN the swiper used to encrypt it.
- It's your responsibility to determine what BDK was used to initialize this device, and from there you'll use the BDK and KSN to rederive the IPEK, which is used to rederive the Session Key, which is finally used to decrypt the message.
There's a lot of technical information to be said about key management, but this isn't the place for that. In some cases your provider/manufacturer (e.g. MagTek) will supply you with swipers that need to be initialized with an IPEK, and your supplier will usually have a manual that walks you through that process. If you're doing encryption/decryption through a third party who also supplies swipers, they may have already loaded the devices with that information; what's more is they may not even given you the BDK that belongs to your device in order to reduce the risk of security threats.
Note: Key management is beyond the scope of this project and this explanation. Whatever you do with your keys, just make sure it's secure.
One methodology I've seen that'll allow you to associate a particular KSN to a BDK is to take the current KSN you've been given, mask it to retrieve the Initial Key Serial Number (IKSN), and look up the BDK in a table that maps IKSNs to BDKs:
Example:
Windows 7 Ultimate Product Key Free Updated. Windows 7 Ultimate Product Key for you. Welcome to visit the official gateway where you can find the 100% working and genuine MS Windows / Office related products. As per routine, today we are going to offer you Updated 2020 Product Key or Serial Key free for MS Windows 7. Windows 7 product keys full working 100% serial keys. Windows 7 is a most famous operating system in the world. So this also detects antivirus and much more. It best operating system in the world. Windows 7 has a user-friendly interface. How to Get Windows 7 Ultimate product key free. Windows 7 ultimate key is a 20 character code. Windows 7 ultimate activation key. Windows 7 Ultimate Product key 100% Working. Windows 7 ultimate continues to be the most favorite operating-system due to its excellent start menu, latest features & most importantly its user-friendly interface, performing it best Windows operating system out there. Windows 7 product key is light and lightweight software application. Windows 7 Ultimate Product Key free Latest Download 32-64 Bit download.
You'd then have a table that looks like:
IKSN | BDK |
---|---|
0xFFFF9876543210E00000 | 0123456789ABCDEFFEDCBA9876543210 |
.. | .. |
From which you could easily grab the BDK
0123456789ABCDEFFEDCBA9876543210
.Algorithm
Note: Assume that all numeric values are hexadecimal numbers, or the representation of a sequence of bytes as a hexadecimal number.
The following are the BDK, KSN, and encrypted track message (cryptogram) we've been given:
Here's an example of the unencrypted track 1 data (cryptogram above), and below that is its value in hex; this is what we'll get after successfully decrypting the cryptogram:
Note: As you're probably already aware, this algorithm is best described using big numbers, which can't be represented as literals in some programming languages (like Java or C#). However, many languages have classes that allow you to represent big numbers in other ways (e.g., java.math.BigInteger, System.Numerics.BigInteger). It's your job to adapt this algorithm so that it can be represented in your language of choice. Two small problems I encountered were ensuring the correct endianness and signedness were being used (this algorithm requires the byte order to be big endian and that unsigned integers are used). I made a utility class called BigInt to do this for me.
First, let's define a few standard functions:
- DES and Triple DES refer to their respective cryptographic algorithms. Most programming languages have access to some implementation of these ciphers either through OpenSSL or Bouncy Castle. These ciphers are initialized with a zeroed out IV of 8 bytes, they're zero-padded, and use Cipher-Block Chaining (CBC). Let's define the signatures for these standard functions that'll be used throughout this algorithm:
DesEncrypt(key, message) -> returns cryptogram
DesDecrypt(key, cryptogram) -> returns message
TripleDesEncrypt(key, message) -> returns cryptogram
TripleDesDecrypt(key, cryptogram) -> returns message
Can A Virtual Hsm Generate Dukpt Keys 2017
First we must create the IPEK given then KSN and BDK:
Now we can get the IPEK:
After that we need a way to get the Session Key (this one is more complicated):
The DeriveKey method finds the IKSN and generates session keys until it gets to the one that corresponds to the current KSN. We define this method as:
Where the GenerateKey method looks like:
And EncryptRegister looks like:
Can A Virtual Hsm Generate Dukpt Keys On Iphone
Then you can generate the Session Key given the IPEK and KSN:
Which can be used to decrypt the cryptogram:
Can A Virtual Hsm Generate Dukpt Keys Download
That's it, you're done!