✔ Add an example of verifying the point G

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bitcookies 2025-05-16 15:47:02 +08:00
parent 18a92b62af
commit d8baf4ddc4
4 changed files with 314 additions and 20 deletions

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@ -11,7 +11,6 @@ Elements in ground field ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.s
<img src="assets/formula/1-dark.svg#gh-dark-mode-only">
</p>
where each coefficients is in ![GF2-inlined](assets/formula/GF2-inlined-light.svg#gh-light-mode-only)![GF2-inlined](assets/formula/GF2-inlined-dark.svg#gh-dark-mode-only). If we use
<p align="center">
@ -19,7 +18,6 @@ where each coefficients is in ![GF2-inlined](assets/formula/GF2-inlined-light.sv
<img src="assets/formula/2-dark.svg#gh-dark-mode-only">
</p>
as the standard basis of the ground field, an element ![A](assets/formula/AA-inlined-light.svg#gh-light-mode-only)![A](assets/formula/AA-inlined-dark.svg#gh-dark-mode-only) in ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only)![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only) can be denoted as
<p align="center">
@ -27,7 +25,6 @@ as the standard basis of the ground field, an element ![A](assets/formula/AA-inl
<img src="assets/formula/3-dark.svg#gh-dark-mode-only">
</p>
---
The irreducible polynomial of composite field ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only) is
@ -37,7 +34,6 @@ The irreducible polynomial of composite field ![GF2p15p17-inlined](assets/formul
<img src="assets/formula/4-dark.svg#gh-dark-mode-only">
</p>
where each coefficients is in ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only)![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only). If we use
<p align="center">
@ -45,7 +41,6 @@ where each coefficients is in ![GF2p15-inlined](assets/formula/GF2p15-inlined-li
<img src="assets/formula/5-dark.svg#gh-dark-mode-only">
</p>
as the standard basis of the composite field, an element ![B](assets/formula/BB-inlined-light.svg#gh-light-mode-only)![B](assets/formula/BB-inlined-dark.svg#gh-dark-mode-only) in ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only) can be denoted as
<p align="center">
@ -53,7 +48,6 @@ as the standard basis of the composite field, an element ![B](assets/formula/BB-
<img src="assets/formula/6-dark.svg#gh-dark-mode-only">
</p>
---
For clarity, we use ![D](assets/formula/DD-inlined-light.svg#gh-light-mode-only)![D](assets/formula/DD-inlined-dark.svg#gh-dark-mode-only) , which is a 255-bits-long integer to denote an element ![B](assets/formula/BB-inlined-light.svg#gh-light-mode-only)![B](assets/formula/BB-inlined-dark.svg#gh-dark-mode-only) in ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only). The map between them is
@ -63,7 +57,6 @@ For clarity, we use ![D](assets/formula/DD-inlined-light.svg#gh-light-mode-only)
<img src="assets/formula/7-dark.svg#gh-dark-mode-only">
</p>
## 2. Elliptic curve over ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only)
The equation of the elliptic curve that WinRAR uses is
@ -73,7 +66,6 @@ The equation of the elliptic curve that WinRAR uses is
<img src="assets/formula/8-dark.svg#gh-dark-mode-only">
</p>
The base point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) is
<p align="center">
@ -81,6 +73,7 @@ The base point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](
<img src="assets/formula/9-dark.svg#gh-dark-mode-only">
</p>
A [verification example](README.VERIFY_Point_G.md) of the base point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) on the curve.
whose order ![n](assets/formula/n-inlined-light.svg#gh-light-mode-only)![n](assets/formula/n-inlined-dark.svg#gh-dark-mode-only) is
@ -89,7 +82,6 @@ whose order ![n](assets/formula/n-inlined-light.svg#gh-light-mode-only)![n](asse
<img src="assets/formula/10-dark.svg#gh-dark-mode-only">
</p>
## 3. Message hash algorithm
We use
@ -99,7 +91,6 @@ We use
<img src="assets/formula/11-dark.svg#gh-dark-mode-only">
</p>
to denote a message whose length is ![l](assets/formula/l-inlined-light.svg#gh-light-mode-only)![l](assets/formula/l-inlined-dark.svg#gh-dark-mode-only). So the SHA1 value of ![M](assets/formula/MM-inlined-light.svg#gh-light-mode-only)![M](assets/formula/MM-inlined-dark.svg#gh-dark-mode-only) should be
<p align="center">
@ -107,7 +98,6 @@ to denote a message whose length is ![l](assets/formula/l-inlined-light.svg#gh-l
<img src="assets/formula/12-dark.svg#gh-dark-mode-only">
</p>
where ![s0,4](assets/formula/13-light.svg#gh-light-mode-only)![s0,4](assets/formula/13-dark.svg#gh-dark-mode-only) are 5 state values when SHA1 outputs. Generally speaking, the final SHA1 value should be the join of these 5 state values while each of state values is serialized in big-endian.
However, WinRAR doesn't serialize the 5 state values. Instead, it use a big integer ![h](assets/formula/h-inlined-light.svg#gh-light-mode-only)![h](assets/formula/h-inlined-dark.svg#gh-dark-mode-only) as the hash of the input message.
@ -117,7 +107,6 @@ However, WinRAR doesn't serialize the 5 state values. Instead, it use a big inte
<img src="assets/formula/15-dark.svg#gh-dark-mode-only">
</p>
## 4. ECC digital signature algorithm
We use ![k](assets/formula/k-inlined-light.svg#gh-light-mode-only)![k](assets/formula/k-inlined-dark.svg#gh-dark-mode-only) to denote private key, ![P](assets/formula/PP-inlined-light.svg#gh-light-mode-only)![P](assets/formula/PP-inlined-dark.svg#gh-dark-mode-only) to denote public key. So there must be
@ -127,7 +116,6 @@ We use ![k](assets/formula/k-inlined-light.svg#gh-light-mode-only)![k](assets/fo
<img src="assets/formula/16-dark.svg#gh-dark-mode-only">
</p>
If we use ![h](assets/formula/h-inlined-light.svg#gh-light-mode-only)![h](assets/formula/h-inlined-dark.svg#gh-dark-mode-only) to denote the hash of input data, WinRAR use the following algorithm to perform signing:
1. Generate a random big integer ![Rnd](assets/formula/Rnd-inlined-light.svg#gh-light-mode-only)![Rnd](assets/formula/Rnd-inlined-dark.svg#gh-dark-mode-only) which satisfies ![RND](assets/formula/18-light.svg#gh-light-mode-only)![RND](assets/formula/18-dark.svg#gh-dark-mode-only).
@ -165,7 +153,6 @@ We use
<img src="assets/formula/26-dark.svg#gh-dark-mode-only">
</p>
to denote input data whose length is ![l](assets/formula/l-inlined-light.svg#gh-light-mode-only)![l](assets/formula/l-inlined-dark.svg#gh-dark-mode-only). WinRAR use it to generate private key ![k](assets/formula/k-inlined-light.svg#gh-light-mode-only)![k](assets/formula/k-inlined-dark.svg#gh-dark-mode-only).
1. We use ![g0-5](assets/formula/27-light.svg#gh-light-mode-only)![g0-5](assets/formula/27-dark.svg#gh-dark-mode-only) to denote 6 32-bits-long integer. So there is
@ -184,7 +171,6 @@ to denote input data whose length is ![l](assets/formula/l-inlined-light.svg#gh-
<img src="assets/formula/33-dark.svg#gh-dark-mode-only">
</p>
Otherwise, when ![l=0](assets/formula/34-light.svg#gh-light-mode-only)![l=0](assets/formula/34-dark.svg#gh-dark-mode-only), we let
<p align="center">
@ -201,7 +187,6 @@ to denote input data whose length is ![l](assets/formula/l-inlined-light.svg#gh-
<img src="assets/formula/37-dark.svg#gh-dark-mode-only">
</p>
We takes the lowest 16 bits of ![S0](assets/formula/38-light.svg#gh-light-mode-only)![S0](assets/formula/38-dark.svg#gh-dark-mode-only) and donote it as ![Kg0](assets/formula/39-light.svg#gh-light-mode-only)![Kg0](assets/formula/39-dark.svg#gh-dark-mode-only).
5. Repeat step 4 again with 14 times.
@ -222,7 +207,6 @@ Private key ![k](assets/formula/k-inlined-light.svg#gh-light-mode-only)![k](asse
<img src="assets/formula/42-dark.svg#gh-dark-mode-only">
</p>
This private key is generated by the algorithm describled in section 5 where the length of data ![T](assets/formula/TT-inlined-light.svg#gh-light-mode-only)![T](assets/formula/TT-inlined-dark.svg#gh-dark-mode-only) is zero.
Public key ![P](assets/formula/PP-inlined-light.svg#gh-light-mode-only)![P](assets/formula/PP-inlined-dark.svg#gh-dark-mode-only) is
@ -297,7 +281,6 @@ The following is the algorithm to generate `rarreg.key`.
<img src="assets/formula/58-dark.svg#gh-dark-mode-only">
</p>
Use the algorithm describled in section 4, with argument ![Temp](assets/formula/Temp-inlined-light.svg#gh-light-mode-only)![Temp](assets/formula/Temp-inlined-dark.svg#gh-dark-mode-only) and private key ![k](assets/formula/k-inlined-light.svg#gh-light-mode-only)![k](assets/formula/k-inlined-dark.svg#gh-dark-mode-only) describled section 6, to get signature ![(rTemp,sTemp)](assets/formula/59-light.svg#gh-light-mode-only)![(rTemp,sTemp)](assets/formula/59-dark.svg#gh-dark-mode-only).
The bit length of ![rTemp](assets/formula/60-light.svg#gh-light-mode-only)![rTemp](assets/formula/60-dark.svg#gh-dark-mode-only) and ![sTemp](assets/formula/61-light.svg#gh-light-mode-only)![sTemp](assets/formula/61-dark.svg#gh-dark-mode-only) shall not be more than 240. Otherwise, repeat this step.
@ -320,9 +303,8 @@ The following is the algorithm to generate `rarreg.key`.
<img src="assets/formula/65-dark.svg#gh-dark-mode-only">
</p>
The final checksum the complement of CRC32 value.
Then convert the checksum to decimal string ![SZchecksum](assets/formula/66-light.svg#gh-light-mode-only)![SZchecksum](assets/formula/66-dark.svg#gh-dark-mode-only). If the length is less than 10, pad character `'0'` until the length is 10.
12. Let ![Data](assets/formula/Data-inlined-light.svg#gh-light-mode-only)![Data](assets/formula/Data-inlined-dark.svg#gh-dark-mode-only) be

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@ -73,6 +73,8 @@ WinRAR 使用了基于 ECC 的签名算法来生成 `rarreg.key` 文件,其使
<img src="assets/formula/9-dark.svg#gh-dark-mode-only">
</p>
基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) 在曲线上的[验证示例](README.VERIFY_Point_G.zh-CN.md)。
基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) 的阶 ![n](assets/formula/n-inlined-light.svg#gh-light-mode-only)![n](assets/formula/n-inlined-dark.svg#gh-dark-mode-only) 为:
<p align="center">

155
README.VERIFY_Point_G.md Normal file
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@ -0,0 +1,155 @@
# Verifying point G lies on the curve
## 1. Composite field, curves and point G
Composite field is ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only).
And the base field is ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only) ![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only), i.e. each element in the domain is a `15-bit` number. The number of extensions is 17, so the entire composite domain element can be viewed as a 17-term polynomial, each term being ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only)![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only).
The equation of the elliptic curve that WinRAR uses is
<p align="center">
<img src="assets/formula/8-light.svg#gh-light-mode-only">
<img src="assets/formula/8-dark.svg#gh-dark-mode-only">
</p>
The base point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) is
<p align="center">
<img src="assets/formula/9-light.svg#gh-light-mode-only">
<img src="assets/formula/9-dark.svg#gh-dark-mode-only">
</p>
## 2. Conversion point G
Convert the point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only)(in large integer format) into the required little-endian representation of `15-bit` segments for the field ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only). A Python for converting the point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) is as follows.
```python
def to_field_repr(val, bits=15, count=17):
mask = (1 << bits) - 1
result = []
for _ in range(count):
result.append(val & mask)
val >>= bits
return result
def print_field(label, field_data):
print(f"{label} = to_field([")
for i in range(len(field_data)):
print(f" 0x{field_data[i]:04X},", end="\n" if (i + 1) % 4 == 0 else " ")
print("])")
Gx_int = 0x56fdcbc6a27acee0cc2996e0096ae74feb1acf220a2341b898b549440297b8cc
Gy_int = 0x20da32e8afc90b7cf0e76bde44496b4d0794054e6ea60f388682463132f931a7
Gx_field = to_field_repr(Gx_int)
Gy_field = to_field_repr(Gy_int)
print_field("Gx", Gx_field)
print()
print_field("Gy", Gy_field)
```
The output can be seen in lines 435 to 456 of the WinRarConfig.hpp file.
```
Gx = to_field([
0x38CC, 0x052F, 0x2510, 0x45AA,
0x1B89, 0x4468, 0x4882, 0x0D67,
0x4FEB, 0x55CE, 0x0025, 0x4CB7,
0x0CC2, 0x59DC, 0x289E, 0x65E3,
0x56FD
])
Gy = to_field([
0x31A7, 0x65F2, 0x18C4, 0x3412,
0x7388, 0x54C1, 0x539B, 0x4A02,
0x4D07, 0x12D6, 0x7911, 0x3B5E,
0x4F0E, 0x216F, 0x2BF2, 0x1974,
0x20DA
])
```
## 3. Verify whether the Point G and PK are on the curve
A Python code to verify whether the base point ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) and PK are on the curve is as follows.
```python
# GF(((2^15)^17))
def gf2_15_add(a, b):
return a ^ b
def gf2_15_mul(a, b):
# Modulus: x^15 + x + 1
res = 0
for i in range(15):
if (b >> i) & 1:
res ^= a << i
# Irreducible polynomial: x^15 + x + 1
for i in range(29, 14, -1):
if (res >> i) & 1:
res ^= 0b1000000000000011 << (i - 15)
return res & 0x7FFF # 15-bit mask
def gf2_15_poly_add(a, b):
return [gf2_15_add(x, y) for x, y in zip(a, b)]
def gf2_15_poly_mul(a, b):
res = [0] * 33
for i in range(17):
for j in range(17):
res[i + j] ^= gf2_15_mul(a[i], b[j])
return res
def gf2_15_17_mod(poly):
# Modulus: y^17 + y^3 + 1
for i in range(len(poly) - 1, 16, -1):
if poly[i]:
poly[i - 17] ^= poly[i]
poly[i - 14] ^= poly[i]
poly[i] = 0
return poly[:17]
def gf2_15_17_mul(a, b):
return gf2_15_17_mod(gf2_15_poly_mul(a, b))
def gf2_15_17_square(a):
return gf2_15_17_mul(a, a)
def gf2_15_17_add(a, b):
return gf2_15_poly_add(a, b)
def gf2_15_17_eq(a, b):
return all(x == y for x, y in zip(a, b))
def is_on_curve(x, y, b):
y2 = gf2_15_17_square(y)
xy = gf2_15_17_mul(x, y)
lhs = gf2_15_17_add(y2, xy)
x2 = gf2_15_17_square(x)
x3 = gf2_15_17_mul(x2, x)
rhs = gf2_15_17_add(x3, b)
return gf2_15_17_eq(lhs, rhs)
def to_field(arr):
assert len(arr) == 17
return arr[:]
# Parameter definition
b = [0x00] * 17
b = [161] + [0]*16 # Constant element in GF((2^15)^17), equivalent to b[0] = 0xA1
Gx = to_field([0x38CC, 0x052F, 0x2510, 0x45AA, 0x1B89, 0x4468, 0x4882, 0x0D67,
0x4FEB, 0x55CE, 0x0025, 0x4CB7, 0x0CC2, 0x59DC, 0x289E, 0x65E3, 0x56FD])
Gy = to_field([0x31A7, 0x65F2, 0x18C4, 0x3412, 0x7388, 0x54C1, 0x539B, 0x4A02,
0x4D07, 0x12D6, 0x7911, 0x3B5E, 0x4F0E, 0x216F, 0x2BF2, 0x1974, 0x20DA])
PKx = to_field([0x3A1A, 0x1109, 0x268A, 0x12F7, 0x3734, 0x75F0, 0x576C, 0x2EA4,
0x4813, 0x3F62, 0x0567, 0x784D, 0x753D, 0x6D92, 0x366C, 0x1107, 0x3861])
PKy = to_field([0x6C20, 0x6027, 0x1B22, 0x7A87, 0x43C4, 0x1908, 0x2449, 0x4675,
0x7933, 0x2E66, 0x32F5, 0x2A58, 0x1145, 0x74AC, 0x36D0, 0x2731, 0x12B6])
# Verification
print("Verify whether the point G is on the curve:", is_on_curve(Gx, Gy, b))
print("Verify whether the PK is on the curve:", is_on_curve(PKx, PKy, b))
```

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@ -0,0 +1,155 @@
# 验证基点G在曲线上
## 1. 复合域、曲线和基点G
复合域为 ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only)。
基域为 ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only)![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only) ,即域中每个元素是一个 `15-bit` 的数字。扩展次数是17所以整个复合域元素可以看作是一个17项的多项式每项都是 ![GF2p15-inlined](assets/formula/GF2p15-inlined-light.svg#gh-light-mode-only)![GF2p15-inlined](assets/formula/GF2p15-inlined-dark.svg#gh-dark-mode-only) 中的数。
曲线方程为:
<p align="center">
<img src="assets/formula/8-light.svg#gh-light-mode-only">
<img src="assets/formula/8-dark.svg#gh-dark-mode-only">
</p>
基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) 为:
<p align="center">
<img src="assets/formula/9-light.svg#gh-light-mode-only">
<img src="assets/formula/9-dark.svg#gh-dark-mode-only">
</p>
## 2. 转换基点G
将基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only)(以大整数形式)转换为 ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-light.svg#gh-light-mode-only) ![GF2p15p17-inlined](assets/formula/GF2p15p17-inlined-dark.svg#gh-dark-mode-only)所需的 `15-bit` 小端表示形式。一个转换基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) 的 Python 脚本如下:
```python
def to_field_repr(val, bits=15, count=17):
mask = (1 << bits) - 1
result = []
for _ in range(count):
result.append(val & mask)
val >>= bits
return result
def print_field(label, field_data):
print(f"{label} = to_field([")
for i in range(len(field_data)):
print(f" 0x{field_data[i]:04X},", end="\n" if (i + 1) % 4 == 0 else " ")
print("])")
Gx_int = 0x56fdcbc6a27acee0cc2996e0096ae74feb1acf220a2341b898b549440297b8cc
Gy_int = 0x20da32e8afc90b7cf0e76bde44496b4d0794054e6ea60f388682463132f931a7
Gx_field = to_field_repr(Gx_int)
Gy_field = to_field_repr(Gy_int)
print_field("Gx", Gx_field)
print()
print_field("Gy", Gy_field)
```
输出结果可以看到正是 WinRarConfig.hpp 文件中 435~456 行的内容:
```
Gx = to_field([
0x38CC, 0x052F, 0x2510, 0x45AA,
0x1B89, 0x4468, 0x4882, 0x0D67,
0x4FEB, 0x55CE, 0x0025, 0x4CB7,
0x0CC2, 0x59DC, 0x289E, 0x65E3,
0x56FD
])
Gy = to_field([
0x31A7, 0x65F2, 0x18C4, 0x3412,
0x7388, 0x54C1, 0x539B, 0x4A02,
0x4D07, 0x12D6, 0x7911, 0x3B5E,
0x4F0E, 0x216F, 0x2BF2, 0x1974,
0x20DA
])
```
## 3. 验证基点G和PK是否在曲线上
一个验证基点 ![G](assets/formula/GG-inlined-light.svg#gh-light-mode-only)![G](assets/formula/GG-inlined-dark.svg#gh-dark-mode-only) 和PK是否在曲线上的 Python 脚本如下:
```python
# GF(((2^15)^17))
def gf2_15_add(a, b):
return a ^ b
def gf2_15_mul(a, b):
# 模 x^15 + x + 1
res = 0
for i in range(15):
if (b >> i) & 1:
res ^= a << i
# 模多项式 x^15 + x + 1
for i in range(29, 14, -1):
if (res >> i) & 1:
res ^= 0b1000000000000011 << (i - 15)
return res & 0x7FFF # 15-bit mask
def gf2_15_poly_add(a, b):
return [gf2_15_add(x, y) for x, y in zip(a, b)]
def gf2_15_poly_mul(a, b):
res = [0] * 33
for i in range(17):
for j in range(17):
res[i + j] ^= gf2_15_mul(a[i], b[j])
return res
def gf2_15_17_mod(poly):
# 模 y^17 + y^3 + 1
for i in range(len(poly) - 1, 16, -1):
if poly[i]:
poly[i - 17] ^= poly[i]
poly[i - 14] ^= poly[i]
poly[i] = 0
return poly[:17]
def gf2_15_17_mul(a, b):
return gf2_15_17_mod(gf2_15_poly_mul(a, b))
def gf2_15_17_square(a):
return gf2_15_17_mul(a, a)
def gf2_15_17_add(a, b):
return gf2_15_poly_add(a, b)
def gf2_15_17_eq(a, b):
return all(x == y for x, y in zip(a, b))
def is_on_curve(x, y, b):
y2 = gf2_15_17_square(y)
xy = gf2_15_17_mul(x, y)
lhs = gf2_15_17_add(y2, xy)
x2 = gf2_15_17_square(x)
x3 = gf2_15_17_mul(x2, x)
rhs = gf2_15_17_add(x3, b)
return gf2_15_17_eq(lhs, rhs)
def to_field(arr):
assert len(arr) == 17
return arr[:]
# 参数定义
b = [0x00] * 17
b = [161] + [0]*16 # GF((2^15)^17) 中的常数元素,等价于 b[0] = 0xA1
Gx = to_field([0x38CC, 0x052F, 0x2510, 0x45AA, 0x1B89, 0x4468, 0x4882, 0x0D67,
0x4FEB, 0x55CE, 0x0025, 0x4CB7, 0x0CC2, 0x59DC, 0x289E, 0x65E3, 0x56FD])
Gy = to_field([0x31A7, 0x65F2, 0x18C4, 0x3412, 0x7388, 0x54C1, 0x539B, 0x4A02,
0x4D07, 0x12D6, 0x7911, 0x3B5E, 0x4F0E, 0x216F, 0x2BF2, 0x1974, 0x20DA])
PKx = to_field([0x3A1A, 0x1109, 0x268A, 0x12F7, 0x3734, 0x75F0, 0x576C, 0x2EA4,
0x4813, 0x3F62, 0x0567, 0x784D, 0x753D, 0x6D92, 0x366C, 0x1107, 0x3861])
PKy = to_field([0x6C20, 0x6027, 0x1B22, 0x7A87, 0x43C4, 0x1908, 0x2449, 0x4675,
0x7933, 0x2E66, 0x32F5, 0x2A58, 0x1145, 0x74AC, 0x36D0, 0x2731, 0x12B6])
# 验证
print("验证基点 G 是否在曲线上:", is_on_curve(Gx, Gy, b))
print("验证 PK 是否在曲线上:", is_on_curve(PKx, PKy, b))
```