用python编程实现ECC的基本运算规则。
时间: 2024-02-23 14:01:48 浏览: 71
下面是 Python 代码实现 ECC 的基本运算规则,同样假设椭圆曲线方程为 y^2 = x^3 + ax + b,其中 p 是模数。
```python
p = 2333 # 模数p
a = 3 # 曲线系数a
b = 5 # 曲线系数b
Gx = 2 # 生成元G的x坐标
Gy = 6 # 生成元G的y坐标
class Point:
def __init__(self, x, y):
self.x = x
self.y = y
def __eq__(self, other):
return self.x == other.x and self.y == other.y
def __add__(self, other):
if self == other:
s = (3 * self.x * self.x + a) % p
t = (2 * self.y) % p
else:
s = (other.y - self.y) % p
t = (other.x - self.x) % p
inv = pow(t, p - 2, p)
lambda_ = (s * inv) % p
x = (lambda_ * lambda_ - self.x - other.x) % p
y = (lambda_ * (self.x - x) - self.y) % p
return Point(x, y)
def __rmul__(self, k):
R = self
k -= 1
while k > 0:
if k & 1:
R = R + self
self = self + self
k >>= 1
return R
def __repr__(self):
return f"({self.x}, {self.y})"
def compress(self):
flag = self.y & 1
return (flag << 8) | self.x
@staticmethod
def decompress(com):
flag = (com >> 8) & 1
x = com & 0xff
y2 = (x * x * x + a * x + b) % p
if flag != (y2 & 1):
y2 = p - y2
y = pow(y2, (p + 1) // 4, p)
return Point(x, y)
# 测试点加法
P = Point(1, 2)
Q = Point(3, 4)
R = P + Q
print(R)
# 测试倍乘
k = 5
S = k * P
print(S)
# 测试点压缩和解压缩
com = P.compress()
P = Point.decompress(com)
print(P)
```
上述代码中,pow(x, y, z) 函数是快速幂算法,用于计算 $x^y \bmod z$ 的值。
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