Secure 4 click
PID: MIKROE-2829
Weight: 24 g
Secure 4 click includes the ATECC608A, a secure CryptoAuthentication™ device from
Microchip, which is equipped with an EEPROM array which can be used for storing of up to 16
keys, certificates, consumption logging, security configurations and other types of secure data.
Access to the various sections of memory can be restricted in several different ways and then the
configuration can be locked permanently, to prevent changes.
The ATECC608A equipped on this click board™, supports the I2C interface with a flexible
command set, that allows use in various security applications, including Network/IoT Node
Endpoint Security, Secure Boot, Small Message Encryption, Key Generation for Software
Download, Ecosystem control, Anti Counterfeiting and similar.
NOTE: The click board™ comes with stacking headers which allow you to combine it with
other click boards™ more easily by using just one mikroBUS™ socket.
How does the click work?
The ATECC608A implements a complete asymmetric key cryptographic signature solution,
based on the Elliptic Curve Cryptography and the ECDSA signature protocol. It also implements
AES-128, SHA256 and multiple SHA derivatives, such as HMSC(SHA), PRF (the key
derivation function in TLS) and HKDF in hardware. It can also generate random private keys
and random numbers, which can be used as a part of the crypto protocol.
Those asymmetric cryptographic operations are accelerated by the ATECC608A hardware and
are calculated up from ten to thousand times faster than with the software running on standard
microprocessors. This prevents the risk of key exposure, which is usually found in standard
microprocessors.
The device is consuming very low current, especially while it is in the sleep mode. The chip
itself uses less than 150nA, in that case. The voltage range which can be used to power up the
Security 4 click, allows for it to work with both 3.3V and 5V capable MCUs.
The chip itself uses a minimal number of pins; only the I2C lines are routed to the mikroBUS™
along with the 3.3V and 5V rails. The device can work with any of these voltages. It can be
selected by soldering a small SMD jumper to the correct position.
The I2C lines are pulled high by the two 4.7KΩ resistors, so no additional pull-up resistors are
needed.
Specifications
Type
EEPROM
Applications
Used for storage of up to 16 keys, certificates, miscellaneous read/write, read‐only or
secret data, consumption logging, and security configurations
On‐board
modules
Microchip ATECC608A IC which includes an EEPROM array
Cryptographic Co‐processor with secure hardware‐based key storage for up to 16 keys,
Key Features certificates or data. Hardware support for the asymmetric sign, verify, key agreement,
unique 72‐bit serial number, fast communication protocol (I2C/GPIO).
Interface
I2C
Input Voltage 3.3V or 5V
Click board
size
M (42.9 x 25.4 mm)
Pinout diagram
This table shows how the pinout on Secure 4 click corresponds to the pinout on the
mikroBUS™ socket (the latter shown in the two middle columns).
Notes
Pin
Pin
Notes
NC
1
AN
PWM
16
NC
NC
2
RST
INT
15
NC
NC
3
CS
RX
14
NC
NC
4
SCK
TX
13
NC
NC
5
MISO
SCL
12
SCL
I2C clock
NC
6
MOSI
SDA
11
SDA
I2C data
Power supply
+3.3V
7
3.3V
5V
10
+5V
Power supply
Ground
GND
8
GND
GND
9
GND
Ground
Secure 4 click maximum ratings
Description
Min Typ Max Unit
1 MHz
Serial clock frequency
Operating temperature ‐40 350 +85 °C
Onboard settings and indicators
Label Name Default
LD1 PWR LED
‐
Description
Power indication LED
JP1 VIO SEL. LEFT Power supply voltage selection, left position 3V3, right position 5V
Software support
We provide a library for the Secure 4 click on our LibStock page, as well as a demo application
(example), developed using MikroElektronika compilers. The demo can run on all the
main MikroElektronika development boards.
Library Description
This click uses CryptoAuthLib from Atmel, slightly modified to work with MikroElektronika
compilers. CryptoAuthLib is designed to cover a wide variety of devices and functions, and it
supports all the features of this click. Basic and commonly used functions are contained in
atca_basic file, and are marked with atcab_ prefix.
Key functions
ATCA_STATUS atcab_random(uint8_t *rand_out) - Returns a random number
ATCA_STATUS atcab_genkey( int slot, uint8_t *pubkey ) - Generates a key in a given
slot
ATCA_STATUS atcab_verify_extern (uint8_t *message, uint8_t *signature,
uint8_t *pubkey, bool *verified) - Verifies a signature using a public key
Examples Description
The example demonstrates various functions of the Secure 4 click. It first performs basic
functions, that can be executed without permanently locking the device. Using the more
advanced functions that are needed to lock the device irreversibly is also shown in the example,
but commented out to prevent accidental locking of the device.
The code snippet shows the use of one of the functions that calculates SHA digest of a short
message and compares it to the precalculated value.
memset (bufferOut,
bufferIn [0] =
bufferIn [1] =
bufferIn [2] =
bufferIn [3] =
0x00, 128);
0x74;
0xba;
0x25;
0x21;
if (atcab_sha(4, bufferIn, bufferOut) == ATCA_SUCCESS)
{
LOG( "rnrn SHA Digest of 0x74BA2521: " );
outputHex (bufferOut, 32);
LOG("rn Expected value of digest: ");
LOG("B1 6A A5 6B E3 88 0D 18 CD 41 E6 83 84 CF 1E C8 C1 76 80 C4
5A");
LOG(" 02 B1 57 5D C1 51 89 23 AE 8B 0E");
}
else
LOG( "rn Generating SHA digest of the message failed..." );
delay_ms (1500);
The full application code, and ready to use projects can be found on our LibStock page.
Other MikroElektronika Libraries used in the example:
MemManager
Conversions
C_String
UART
Additional notes and information
Depending on the development board you are using, you may need USB UART click, USB
UART 2 click or RS232 click to connect to your PC, for development systems with no UART to
USB interface available on the board. The terminal available in all MikroElektronika compilers,
or any other terminal application of your choice, can be used to read the message.
https://www.mikroe.com/secure‐4‐click 12‐20‐17
