Introduction

Smart factories, industrial and medical applications employ the flexibility and high performance of modern FPGAs. As these systems become increasingly connected, security emerges as a paramount feature to protect IP, enable system features using software and prevent counterfeiting. The Alcatraz (MAXREFDES34#) subsystem reference design uses the DS28E15 to immediately implement SHA-256 authentication on Xilinx^®FPGAs. The DS28E15 communicates over the single-contact 1-Wire^® bus, reducing the number of pins necessary to carry out the solution. The reference code defines a combined SHA-256 processor and 1-Wire Master on the host FPGA.

Figure 1. The Alcatraz subsystem design block diagram with development platform.

Features	Applications
SHA-256 authentication Single-contact 1-Wire interface Example source code Pmod™-compatible form factor Competitive Advantages Crypto-strong authentication Single pin count interface Fast performance with hardware acceleration	Counterfeit protection Peripheral authentication IP protection License and feature management

Detailed Description of Hardware

Alcatraz interfaces with FPGA development boards using a 6-pin Pmod connector as illustrated. When plugging Alcatraz into a host board, make sure to correctly align the pins with the host Pmod connector, as shown in Figure 2.

Figure 2. The Alcatraz subsystem design correctly inserted into the MicroZed development platform.

Table 1 shows the supported platforms and ports.

Table 1. Supported Platforms and Ports

Supported Platforms	Ports
LX9™ 3 platform (Spartan®-6)	J5
MicroZed™ platform (Zynq®-7000)	J5

For symmetric authentication schemes like SHA-256, protection of both the secure authenticator secret key, along with the FPGA secret key, are important. Symmetric authentication implementations with poor FPGA secret key security can be risky. To this end, the DS28E15 uses DeepCover^® technology to protect against invasive and noninvasive attacks on its secret key; the reference design spells out various techniques to protect the FPGA secret key.

Detailed Description of Firmware for LX9 Platform

Table 1 shows currently supported platforms and ports. Support for additional platforms may be added periodically under Firmware Files in the All Design Files section.

The firmware allows for immediate interfacing to the hardware. The firmware is written in Verilog, developed using the Xilinx SDK tool, based on the Eclipse^™ open source standard.

The firmware program sequence is used to compute and lock the secret (CLS), write page data to the DS28E15, and authenticate the DS28E15. The complete source code speeds customer development. Code documentation resides in the corresponding firmware platform files.

Detailed Description of Firmware for MicroZed Platform

The Alcatraz firmware design also supports the MicroZed kit and targets an ARM^® Cortex^® -A9 processor placed inside a Xilinx Zynq system-on-chip (SoC).

The firmware allows for immediate interfacing to the hardware. The firmware is written in C, developed using the Xilinx SDK tool, based on the Eclipse^™ open source standard.

The firmware program sequence is used to compute and lock the secret (CLS), write page data to the DS28E15, and authenticate the DS28E15. The complete source code speeds customer development. Code documentation resides in the corresponding firmware platform files.

Quick Start

Required equipment:

• Windows^® PC with two USB ports
• Alcatraz (MAXREFDES34#) board
• Alcatraz-supported platform (i.e., LX9 development kit or MicroZed kit)

Detailed setup and programming instructions are included in the README.txt file within the provided firmware files.

1-Wire is a registered trademark of Maxim Integrated Products, Inc.
ARM is a registered trademark and registered service mark of ARM Limited.
Cortex is a registered trademark of ARM Limited. 
DeepCover is a registered trademark of Maxim Integrated Products, Inc.
Eclipse is a trademark of Eclipse Foundation, Inc.
HyperTerminal is a registered trademark of Hilgraeve, Incorporated.
ISE is a registered trademark of Xilinx, Inc.
Pmod is a trademark of Digilent Inc.
Spartan is a registered trademark of Xilinx, Inc.
Windows is a registered trademark and registered service mark of Microsoft Corporation.
Windows XP is a registered trademark and registered service mark of Microsoft Corporation.
Xilinx is a registered trademark and registered service mark of Xilinx, Inc.
ZedBoard is a trademark of ZedBoard.org.
Zynq is a registered trademarkof Xilinx, Inc.