tinyECC - Elliptic Curve Cryptography for Arduino Micro-controllers.

This is a library for implementing Elliptic Curve Cryptography (ECC) and Elliptic Curve Digital Signature Algorithm (ECDSA) on Arduino-based microcontrollers.

Features

Elliptic Curve Cryptography for Arduino-based microcontrollers.
Elliptic Curve Digital Signature Algorithm.
Three different mapping tables to choose from as per your application.
Mapping table is stored in program memory to save RAM space
Easy-to-use

How to use Library

Create an object of class tinyECC:

tinyECC e;    // object e of class tinyECC

Encryption

e.plaintext = "Hello World!"; // Assign to plaintext

e.encrypt();                   // Encrypt plaintext and store result in ciphertext

Serial.println(e.ciphertext); // Display ciphertext

Decryption

e.ciphertext = "........." ;   // Assign encrypted text to ciphertext

e.decrypt();                   // Decrypt ciphertext and store result in plaintext

Serial.println(e.plaintext); // Display plaintext

Signature Generation

e.plaintext = "Hello World!"; // Assign to plaintext

e.genSig();                   // Generate Signature

Serial.println(String(e.Sig[0])+","+String(e.Sig[1])); // Display generated Signature (Signature is a 2-element array)

Signature Verificcation

e.plaintext = "Hello World!"; // Assign to plaintext

e.Sig[0] = 67, e.Sig[1] = 27;   // Assign Signature

e.verifySig();                 // Returns true if signature verified, else returns false.

Mapping Tables

There are three mapping table options:

1. 256-element mapping table for ASCII-256 characters. This covers all keyboard characters plus special greek and math symbols.
1. 128-element mapping table for ASCII-127 characters. This covers all the keyboard and commonly-used characters
1. 10-element mapping table for digits from 0 to 9. Use this if you are dealing purely with numbers in your plaintext.

How to set mapping table:

To set mapping table, edit the tinyECC_mapping_table.h file. Uncomment the appropriate line to define your mapping table in the tinyECC_mapping_table.h file as shown below:

//Mapping Table for 0-255 ASCII characters. Includes support for special characters. 

#define MAPPING_TABLE_TYPE  MAPPING_TABLE_256

#define MAPPING_TABLE_SIZE  MAPPING_TABLE_256_SIZE

//Mapping Table for 0-127 ASCII characters. Most of the commonly used keyboard characters are covered in this range.

//#define MAPPING_TABLE_TYPE  MAPPING_TABLE_128

//#define MAPPING_TABLE_SIZE  MAPPING_TABLE_128_SIZE

//Mapping Table for '0'-'9' characters. Use when string contains only numbers.

//#define MAPPING_TABLE_TYPE  MAPPING_TABLE_10

//#define MAPPING_TABLE_SIZE  MAPPING_TABLE_10_SIZE

Important Note:

Encryption and decryption, being intensive processes, will take significant time when executed on Arduino-based microcontrollers.
Encryption and decryption times will increase with increase in the length of plaintext and ciphertext.
Mapping tables occupy space in program memory. The mapping table will occupy 1024, 512, or 40 bytes in your program memory based on 256, 128, 10-element mapping tables respectively.
Keep a track of plaintext and ciphertext lengths as these can consume significant space in your RAM. Keep plaintext length within limits.

ShubhamAnnigeri/tinyECC-ArduinoIDE