func main() {
//Initalize our ciphertext
c := "jnfcztiecytrtkxbrvwgoxjvbuyducvsridemeatptnxxouhkxkhosujeezvwukwoqpekfyrvojliwojonvxijzgrjusxehs otx"
//Encode our ciphertext
i := coding.Encode(c)
//make the key slice
k := make([]int, 7)
//Since the ordering doesn't matter because n-c-v=n-v-c
//We can decrypt everything with the Caesar cipher first
//We check all possible caesar ciphers. then visually inspect for english visually.
//When I wrote this I wasn't sure it was safe to assume caeser was always a shift by 3 as most of what I saw when I googled to double check was using it more generally as simple shift ciphers.
for j := 0; j < 27; j++ {
temp := shift(i, j)
//Because we know some of the format of the message we can assume that k[0] will decrypt c[7] to ' '
//So we can just hardcode the value.
//After we know one decrpytion, it is simple to decrypt each key based on our knowledge of the key permutation.
//phi = [5, 6, 4, 2, 1, 3, 0]
k[0] = (temp[7] - 26 + 27) % 27 //assume That k[0] will decrypt a ' '
k[5] = (temp[0] - k[0] + 27) % 27
k[3] = (temp[5] - k[5] + 27) % 27
k[2] = (temp[3] - k[3] + 27) % 27
k[4] = (temp[2] - k[2] + 27) % 27
k[1] = (temp[4] - k[4] + 27) % 27
k[6] = (temp[1] - k[1] + 27) % 27
if temp[6]-k[6] == k[0] { //Verify that our assumption is correct
fmt.Println("Good")
}
temp = decryptV(temp, k)
fmt.Println(j, (temp[7]-26+27)%27, coding.Decode(temp))
}
}
func shift(base []rune, shift int) string {
r := make([]int, len(base))
//Encode the string so that shifting is simple
s := coding.Encode(string(base))
for i, k := range s {
//i is the index, k is s[i]
r[i] = (k + shift) % 27
}
//Decode the shifted string while returning i.
return coding.Decode(r)
}
func main() {
//I think this is pretty self explanatory (s is a string, but you probably are used to this from python)
s := "qualitatively"
//coding.Encode returns an int slice, which is basically just an array that can be resized.
i := coding.Encode(s)
fmt.Println(i)
//Initalize c as an int slice.
c := []int{19, 7, 4, 26, 18, 4, 2, 17, 4, 19, 26, 22, 14, 17, 3, 26, 8, 18, 26, 1, 4, 11, 0, 1, 14, 17}
//decode, which returns a string
i2 := coding.Decode(c)
fmt.Println(i2)
}
func main() {
//initialize x with our seed values
x := []int{341, 817, 38, 471, 50, 277, 43, 491, 796, 812}
//Initialize c with our ciphertext
c := []int{346, 825, 55, 489, 69, 303, 60, 511, 807, 816, 299, 556, 142, 165, 459, 605, 76, 491, 997, 182, 144, 548, 991, 788, 222, 584, 410, 439, 403, 755, 986, 91, 990, 719, 833, 715, 611, 890, 78, 436, 63, 220, 32, 32, 49, 865, 909, 420, 60}
for i, k := range c {
//Decode our ciphertext
c[i] = (P + k - x[0]) % P //Add P to make sure it stays positive
//Increment our shift register
x = shiftReg(x)
}
fmt.Println(coding.Decode(c))
}