.. | ||
scripts | ||
test | ||
.gitignore | ||
asm_arm.inc | ||
asm_avr.inc | ||
btstack_config_uECC.h | ||
emk_project.py | ||
emk_rules.py | ||
LICENSE.txt | ||
README.md | ||
uECC.c | ||
uECC.h |
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 5 standard curves: secp160r1, secp192r1, secp224r1, 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
anduECC_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 touECC_asm_small
oruECC_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 touECC_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.
secp160r1 | secp192r1 | secp256r1 | secp256k1 | |
---|---|---|---|---|
ECDH: | 2.3 | 2.7 | 7.9 | 6.5 |
ECDSA sign: | 2.8 | 3.1 | 8.6 | 7.2 |
ECDSA verify: | 2.7 | 3.2 | 9.2 | 7.0 |
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.
secp160r1 | secp192r1 | secp256r1 | secp256k1 | |
---|---|---|---|---|
ECDH time (ms): | 470 | 810 | 2220 | 1615 |
Code size (bytes): | 10768 | 13112 | 20886 | 21126 |
ECDH (small)
In these tests, uECC_ASM
was defined to uECC_asm_small
and ECC_SQUARE_FUNC
was defined to 0
in all cases.
secp160r1 | secp192r1 | secp256r1 | secp256k1 | |
---|---|---|---|---|
ECDH time (ms): | 1250 | 1810 | 4790 | 4700 |
Code size (bytes): | 3244 | 3400 | 5274 | 3426 |
ECDSA (fast)
In these tests, uECC_ASM
was defined to uECC_asm_fast
and ECC_SQUARE_FUNC
was defined to 1
in all cases.
secp160r1 | secp192r1 | secp256r1 | secp256k1 | |
---|---|---|---|---|
ECDSA sign time (ms): | 555 | 902 | 2386 | 1773 |
ECDSA verify time (ms): | 590 | 990 | 2650 | 1800 |
Code size (bytes): | 13246 | 14798 | 22594 | 22826 |
ECDSA (small)
In these tests, uECC_ASM
was defined to uECC_asm_small
and ECC_SQUARE_FUNC
was defined to 0
in all cases.
secp160r1 | secp192r1 | secp256r1 | secp256k1 | |
---|---|---|---|---|
ECDSA sign time (ms): | 1359 | 1931 | 4998 | 4904 |
ECDSA verify time (ms): | 1515 | 2160 | 5700 | 5220 |
Code size (bytes): | 5690 | 5054 | 6980 | 5080 |