extlibs/tinydtls/ecc/README.md

   1 micro-ecc
   2 ==========
   3
   4 A small and fast ECDH and ECDSA implementation for 8-bit, 32-bit, and 64-bit processors.
   5
   6 The old version of micro-ecc can be found in the "old" branch.
   7
   8 Features
   9 --------
  10
  11  * Resistant to known side-channel attacks.
  12  * Written in C, with optional GCC inline assembly for AVR, ARM and Thumb platforms.
  13  * Supports 8, 32, and 64-bit architectures.
  14  * Small code size.
  15  * No dynamic memory allocation.
  16  * Support for 4 standard curves: secp160r1, secp192r1, secp256r1, and secp256k1.
  17  * BSD 2-clause license.
  18
  19 Usage Notes
  20 -----------
  21 ### Point Representation ###
  22 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.
  23
  24 Private keys are represented in the standard format.
  25
  26 ### Using the Code ###
  27
  28 I recommend just copying (or symlink) uECC.h, uECC.c, and the appropriate asm\_&lt;arch&gt;\_.inc (if any) into your project. Then just `#include "uECC.h"` to use the micro-ecc functions.
  29
  30 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).
  31
  32 See uECC.h for documentation for each function.
  33
  34 ### Compilation Notes ###
  35
  36  * Should compile with any C/C++ compiler that supports stdint.h (this includes Visual Studio 2013).
  37  * 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).
  38  * 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).
  39  * 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).
  40  * When compiling for AVR with inline assembly enabled, you must have optimizations enabled (compile with `-O1` or higher).
  41  * When building for Windows, you will need to link in the `advapi32.lib` system library.
  42
  43 ARM Performance
  44 ---------------
  45
  46 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.
  47
  48 <table>
  49         <tr>
  50                 <th></th>
  51                 <th>secp160r1</th>
  52                 <th>secp192r1</th>
  53                 <th>secp256r1</th>
  54                 <th>secp256k1</th>
  55         </tr>
  56         <tr>
  57                 <td><em>ECDH:</em></td>
  58                 <td>2.3</td>
  59                 <td>2.7</td>
  60                 <td>7.9</td>
  61                 <td>6.5</td>
  62         </tr>
  63         <tr>
  64                 <td><em>ECDSA sign:</em></td>
  65                 <td>2.8</td>
  66                 <td>3.1</td>
  67                 <td>8.6</td>
  68                 <td>7.2</td>
  69         </tr>
  70         <tr>
  71                 <td><em>ECDSA verify:</em></td>
  72                 <td>2.7</td>
  73                 <td>3.2</td>
  74                 <td>9.2</td>
  75                 <td>7.0</td>
  76         </tr>
  77 </table>
  78
  79 AVR Performance
  80 ---------------
  81
  82 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.
  83
  84 #### ECDH (fast) ####
  85
  86 In these tests, `uECC_ASM` was defined to `uECC_asm_fast` and `ECC_SQUARE_FUNC` was defined to `1` in all cases.
  87
  88 <table>
  89         <tr>
  90                 <th></th>
  91                 <th>secp160r1</th>
  92                 <th>secp192r1</th>
  93                 <th>secp256r1</th>
  94                 <th>secp256k1</th>
  95         </tr>
  96         <tr>
  97                 <td><em>ECDH time (ms):</em></td>
  98                 <td>470</td>
  99                 <td>810</td>
 100                 <td>2220</td>
 101                 <td>1615</td>
 102         </tr>
 103         <tr>
 104                 <td><em>Code size (bytes):</em></td>
 105                 <td>10768</td>
 106                 <td>13112</td>
 107                 <td>20886</td>
 108                 <td>21126</td>
 109         </tr>
 110 </table>
 111
 112 #### ECDH (small) ####
 113
 114 In these tests, `uECC_ASM` was defined to `uECC_asm_small` and `ECC_SQUARE_FUNC` was defined to `0` in all cases.
 115
 116 <table>
 117         <tr>
 118                 <th></th>
 119                 <th>secp160r1</th>
 120                 <th>secp192r1</th>
 121                 <th>secp256r1</th>
 122                 <th>secp256k1</th>
 123         </tr>
 124         <tr>
 125                 <td><em>ECDH time (ms):</em></td>
 126                 <td>1250</td>
 127                 <td>1810</td>
 128                 <td>4790</td>
 129                 <td>4700</td>
 130         </tr>
 131         <tr>
 132                 <td><em>Code size (bytes):</em></td>
 133                 <td>3244</td>
 134                 <td>3400</td>
 135                 <td>5274</td>
 136                 <td>3426</td>
 137         </tr>
 138 </table>
 139
 140 #### ECDSA (fast) ####
 141
 142 In these tests, `uECC_ASM` was defined to `uECC_asm_fast` and `ECC_SQUARE_FUNC` was defined to `1` in all cases.
 143
 144 <table>
 145         <tr>
 146                 <th></th>
 147                 <th>secp160r1</th>
 148                 <th>secp192r1</th>
 149                 <th>secp256r1</th>
 150                 <th>secp256k1</th>
 151         </tr>
 152         <tr>
 153                 <td><em>ECDSA sign time (ms):</em></td>
 154                 <td>555</td>
 155                 <td>902</td>
 156                 <td>2386</td>
 157                 <td>1773</td>
 158         </tr>
 159         <tr>
 160                 <td><em>ECDSA verify time (ms):</em></td>
 161                 <td>590</td>
 162                 <td>990</td>
 163                 <td>2650</td>
 164                 <td>1800</td>
 165         </tr>
 166         <tr>
 167                 <td><em>Code size (bytes):</em></td>
 168                 <td>13246</td>
 169                 <td>14798</td>
 170                 <td>22594</td>
 171                 <td>22826</td>
 172         </tr>
 173 </table>
 174
 175 #### ECDSA (small) ####
 176
 177 In these tests, `uECC_ASM` was defined to `uECC_asm_small` and `ECC_SQUARE_FUNC` was defined to `0` in all cases.
 178
 179 <table>
 180         <tr>
 181                 <th></th>
 182                 <th>secp160r1</th>
 183                 <th>secp192r1</th>
 184                 <th>secp256r1</th>
 185                 <th>secp256k1</th>
 186         </tr>
 187         <tr>
 188                 <td><em>ECDSA sign time (ms):</em></td>
 189                 <td>1359</td>
 190                 <td>1931</td>
 191                 <td>4998</td>
 192                 <td>4904</td>
 193         </tr>
 194         <tr>
 195                 <td><em>ECDSA verify time (ms):</em></td>
 196                 <td>1515</td>
 197                 <td>2160</td>
 198                 <td>5700</td>
 199                 <td>5220</td>
 200         </tr>
 201         <tr>
 202                 <td><em>Code size (bytes):</em></td>
 203                 <td>5690</td>
 204                 <td>5054</td>
 205                 <td>6980</td>
 206                 <td>5080</td>
 207         </tr>
 208 </table>