micro-ecc ========== A small and fast ECDH and ECDSA implementation for 8-bit, 32-bit, and 64-bit processors. The old version of micro-ecc can be found in the "old" branch. Features -------- * Resistant to known side-channel attacks. * Written in C, with optional GCC inline assembly for AVR, ARM and Thumb platforms. * Supports 8, 32, and 64-bit architectures. * Small code size. * No dynamic memory allocation. * Support for 4 standard curves: secp160r1, secp192r1, secp256r1, and secp256k1. * BSD 2-clause license. Usage Notes ----------- ### Point Representation ### Compressed points are represented in the standard format as defined in http://www.secg.org/collateral/sec1_final.pdf; uncompressed points are represented in standard format, but without the `0x04` prefix. `uECC_make_key()`, `uECC_shared_secret()`, `uECC_sign()`, and `uECC_verify()` only handle uncompressed points; you can use `uECC_compress()` and `uECC_decompress()` to convert between compressed and uncompressed point representations. Private keys are represented in the standard format. ### Using the Code ### I recommend just copying (or symlink) uECC.h, uECC.c, and the appropriate asm\_<arch>\_.inc (if any) into your project. Then just `#include "uECC.h"` to use the micro-ecc functions. For use with Arduino, you can just create a symlink to the `uECC` directory in your Arduino `libraries` directory. You can then use uECC just like any other Arduino library (uECC should show up in the **Sketch**=>**Import Library** submenu). See uECC.h for documentation for each function. ### Compilation Notes ### * Should compile with any C/C++ compiler that supports stdint.h (this includes Visual Studio 2013). * If you want to change the defaults for `uECC_CURVE` and `uECC_ASM`, you must change them in your Makefile or similar so that uECC.c is compiled with the desired values (ie, compile uECC.c with `-DuECC_CURVE=uECC_secp256r1` or whatever). * When compiling for a Thumb-1 platform with inline assembly enabled (ie, `uECC_ASM` is defined to `uECC_asm_small` or `uECC_asm_fast`), you must use the `-fomit-frame-pointer` GCC option (this is enabled by default when compiling with `-O1` or higher). * When compiling for an ARM/Thumb-2 platform with fast inline assembly enabled (ie, `uECC_ASM` is defined to `uECC_asm_fast`), you must use the `-fomit-frame-pointer` GCC option (this is enabled by default when compiling with `-O1` or higher). * When compiling for AVR with inline assembly enabled, you must have optimizations enabled (compile with `-O1` or higher). * When building for Windows, you will need to link in the `advapi32.lib` system library. ARM Performance --------------- All tests were built using gcc 4.8.2 with `-O3`, and were run on a Raspberry Pi B+. `uECC_ASM` was defined to `uECC_asm_fast` and `ECC_SQUARE_FUNC` was defined to `1` in all cases. All times are in milliseconds. <table> <tr> <th></th> <th>secp160r1</th> <th>secp192r1</th> <th>secp256r1</th> <th>secp256k1</th> </tr> <tr> <td><em>ECDH:</em></td> <td>2.3</td> <td>2.7</td> <td>7.9</td> <td>6.5</td> </tr> <tr> <td><em>ECDSA sign:</em></td> <td>2.8</td> <td>3.1</td> <td>8.6</td> <td>7.2</td> </tr> <tr> <td><em>ECDSA verify:</em></td> <td>2.7</td> <td>3.2</td> <td>9.2</td> <td>7.0</td> </tr> </table> AVR Performance --------------- All tests were built using avr-gcc 4.8.1 with `-Os`, and were run on a 16 MHz ATmega256RFR2. Code size refers to the space used by micro-ecc code and data. #### ECDH (fast) #### In these tests, `uECC_ASM` was defined to `uECC_asm_fast` and `ECC_SQUARE_FUNC` was defined to `1` in all cases. <table> <tr> <th></th> <th>secp160r1</th> <th>secp192r1</th> <th>secp256r1</th> <th>secp256k1</th> </tr> <tr> <td><em>ECDH time (ms):</em></td> <td>470</td> <td>810</td> <td>2220</td> <td>1615</td> </tr> <tr> <td><em>Code size (bytes):</em></td> <td>10768</td> <td>13112</td> <td>20886</td> <td>21126</td> </tr> </table> #### ECDH (small) #### In these tests, `uECC_ASM` was defined to `uECC_asm_small` and `ECC_SQUARE_FUNC` was defined to `0` in all cases. <table> <tr> <th></th> <th>secp160r1</th> <th>secp192r1</th> <th>secp256r1</th> <th>secp256k1</th> </tr> <tr> <td><em>ECDH time (ms):</em></td> <td>1250</td> <td>1810</td> <td>4790</td> <td>4700</td> </tr> <tr> <td><em>Code size (bytes):</em></td> <td>3244</td> <td>3400</td> <td>5274</td> <td>3426</td> </tr> </table> #### ECDSA (fast) #### In these tests, `uECC_ASM` was defined to `uECC_asm_fast` and `ECC_SQUARE_FUNC` was defined to `1` in all cases. <table> <tr> <th></th> <th>secp160r1</th> <th>secp192r1</th> <th>secp256r1</th> <th>secp256k1</th> </tr> <tr> <td><em>ECDSA sign time (ms):</em></td> <td>555</td> <td>902</td> <td>2386</td> <td>1773</td> </tr> <tr> <td><em>ECDSA verify time (ms):</em></td> <td>590</td> <td>990</td> <td>2650</td> <td>1800</td> </tr> <tr> <td><em>Code size (bytes):</em></td> <td>13246</td> <td>14798</td> <td>22594</td> <td>22826</td> </tr> </table> #### ECDSA (small) #### In these tests, `uECC_ASM` was defined to `uECC_asm_small` and `ECC_SQUARE_FUNC` was defined to `0` in all cases. <table> <tr> <th></th> <th>secp160r1</th> <th>secp192r1</th> <th>secp256r1</th> <th>secp256k1</th> </tr> <tr> <td><em>ECDSA sign time (ms):</em></td> <td>1359</td> <td>1931</td> <td>4998</td> <td>4904</td> </tr> <tr> <td><em>ECDSA verify time (ms):</em></td> <td>1515</td> <td>2160</td> <td>5700</td> <td>5220</td> </tr> <tr> <td><em>Code size (bytes):</em></td> <td>5690</td> <td>5054</td> <td>6980</td> <td>5080</td> </tr> </table>