Overview

Like most computer hardware, the price of smart cards is steadily decreasing, while performance and capacity are improving all the time. You can now buy a fully-functional computer, the size of your thumb-nail, for just a euro or two. However, before the Microprocessor arrived, the cost of developing software for smart cards was out of all proportion to the cost of the hardware. A typical development project might take six months and cost a quarter of a million euros. This was a major barrier to the widespread use and acceptance of smart cards.

But now you can program your own smart card in an afternoon, with no previous experience required. If you can program in Basic, you can design and implement a custom smart card application. With ZeitControl’s Microprocessor, the development cycle of writing code, downloading, and testing takes a few minutes instead of weeks.

The Smart Card Environment

Obviously, programming a smart card is not the same as programming a desktop computer. It has no keyboard or screen, for a start. So how does a smart card receive its input and communicate its output? It talks to the outside world through its bi-directional I/O contact. Communication takes place at 9600 baud or more, according to the T=0 and T=1 protocols defined in ISO/IEC standards 7816-3 and 7816-4. But this is completely invisible to the Basic programmer – all you have to do is define a command in the card, and program it like an ordinary Basic procedure. Then you can call this command from a ZC-Basic program running on the PC. Again, the command is called as if it was an ordinary procedure.

The Microprocessor operating system takes care of all the communications for you. It will even encrypt and decrypt the commands and responds if you ask it to. All you have to do is specify a different two-byte ID for each command that you define. (If you are familiar with ISO/IEC 7816-4: Interindustry commands for interchange, you will know these two bytes as CLA and INS, for Class and Instruction.)

Here is a simple example. Suppose you run a discount warehouse, and you are issuing the Microprocessor to members to store pre-paid credits. You will want a command that returns the number of credits left in the card. So you might define the command GetCustomerCredits, and give it an ID of &H20 &H01 (&H is the hexadecimal prefix):

You can call this command from the PC with the following code:

The value &H9000 is defined in ISO/IEC 7816-4 as the status code for a successful command. This value is automatically returned to the caller unless the ZC-Basic code specifies otherwise. The return value from a command should always be checked, even if the command itself has no error conditions – for instance, the card may have been removed from the reader.

It’s as simple as that. Of course, there is a lot more going on below the surface, but you don’t have to know about it to write a Microprocessor application.

Technical Summary

All Microprocessor families (Compact, Enhanced, and Professional) contain:

• a full implementation of the T=1 block-level communications protocol defined in ISO/IEC 7816-3: Electronic signals and transmission protocols, including chaining, retries, and WTX requests;
• a command dispatcher built around the structures defined in ISO/IEC 7816-4: Interindustry commands for interchange (CLA INS P1 P2 [Lc IDATA] [Le] );
• built-in commands for loading EEPROM, enabling encryption, etc.;
• a Virtual Machine for the execution of ZeitControl’s P-Code;
• code for the automatic encryption and decryption of commands and responses, using the AES, DES, or SG-LFSR symmetric-key algorithm.

Enhanced and Professional Microprocessors contain in addition:

• a directory-based, DOS-like file system;
• IEEE-compatible floating-point arithmetic.

The functionality of the Enhanced Microprocessor family can be further extended using Plug-In Libraries.

Professional Microprocessors contain in addition:

• a Public-Key algorithm (RSA or EC);
• a full implementation of the T=0 byte-level communications protocol defined in ISO/IEC 7816-3: Electronic signals and transmission protocols;

• the SHA-1 Secure Hash Algorithm.

The data sheet on the next page contains details of available Microprocessors versions, and the cryptographic algorithms that they support.

Development Software

The ZeitControl MultiDebugger software support package consists of:

• ZCPDE, the Professional Development Environment;
• ZCMDTERM and ZCMDCARD, debuggers for Terminal programs and Microprocessor programs;
• ZCMBASIC, the compiler for the ZC-Basic language;
• ZCMSIM, for low-level simulation of Terminal and Microprocessor programs;
• BCLOAD, for downloading P-Code to the Microprocessor;
• KEYGEN, a program that generates random keys for use in encryption;
• BCKEYS, for downloading cryptographic keys to the Compact and Enhanced Microprocessors.

Compact Microprocessor

Enhanced Microprocessor

¹ EC-FSA: Fast Signature Algorithm for Elliptic Curve Cryptography

Plug-In Libraries for the Enhanced Microprocessor: EC-161, AES, SHA-1, IDEA

Professional Microprocessor

¹ Single-to-String conversion not supported

MultiApplication Microprocessor

Public-Key Algorithms

Symmetric-Key Algorithms

Data Hashing Algorithms

Communication Protocols

All You Need To Know About Magstripe Guide to Magnetic Encoding on Cards


Magnetic Track Specifications


California Driver License's Format (DMV)

Driver License's Format Recommended by (AAMVA)

Credit Card Format

© Copyright 1989 To Present Escan Technologies Corp. All Rights Reserved