├── .gitignore
├── go.mod
├── main_test.go
└── main.go


/.gitignore:
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1 | .idea
2 | .swp
3 | 


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/go.mod:
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1 | module github.com/cor/sindecrypt
2 | 
3 | go 1.16
4 | 


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/main_test.go:
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 1 | package main
 2 | 
 3 | import (
 4 | 	"fmt"
 5 | 	"testing"
 6 | )
 7 | 
 8 | func TestEncryptIdentity(t *testing.T) {
 9 | 
10 | 	for k := 0; k < 100000; k++ {
11 | 		for x := 0; x <= 9; x++ {
12 | 			if decryptDigit(encryptDigit(x, k), k) != x {
13 | 				t.Fatalf("decryptDigit(encryptDigit(x, k), k) != x. %v %v", x, k)
14 | 			}
15 | 		}
16 | 	}
17 | }
18 | 
19 | func TestCheckDigit(t *testing.T) {
20 | 	tt := 1_234_567_890
21 | 
22 | 	fmt.Println(encrypt("0612345678"))
23 | 
24 | 	correct1 := checkDigit(0, 9, 0, 0, tt)
25 | 	correct2 := checkDigit(6, 4, 0, 1, tt)
26 | 
27 | 	if !correct1 {
28 | 		t.Fatalf("incorrect 1")
29 | 	}
30 | 
31 | 	if !correct2 {
32 | 		t.Fatalf("incorrect 2")
33 | 	}
34 | }
35 | 


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/main.go:
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 1 | package main
 2 | 
 3 | import (
 4 | 	"fmt"
 5 | 	"math"
 6 | 	"strconv"
 7 | )
 8 | 
 9 | func main() {
10 | 
11 | 	for t := 1_234_567_889; t <= 9_999_999_999; t++ {
12 | 		correct1 := checkDigit(0, 9, 0, 0, t)
13 | 		correct2 := checkDigit(6, 4, 0, 1, t)
14 | 
15 | 		//correct3 := check(4, 0, 1, 1, t)
16 | 		//correct4 := check(3, 6, 1, 2, t)
17 | 
18 | 		if correct1 && correct2 {
19 | 			//options = append(options, t)
20 | 			//fmt.Println(t)
21 | 
22 | 			//fmt.Println(t)
23 | 			if t == 1_234_567_890 {
24 | 				fmt.Println("found")
25 | 			}
26 | 		}
27 | 	}
28 | }
29 | 
30 | func digitKey(t int, i int, j int) int {
31 | 	s := math.Sin(float64(t + i))
32 | 	k := getFloatDigit(s, j+1)
33 | 	return k
34 | }
35 | 
36 | func encryptDigit(x int, k int) int {
37 | 	return (x + k) % 10
38 | }
39 | 
40 | func decryptDigit(y int, k int) int {
41 | 	return (y - (k % 10) + 10) % 10
42 | }
43 | 
44 | func checkDigit(x int, y int, i int, j int, t int) bool {
45 | 	k := digitKey(t, i, j)
46 | 	d := decryptDigit(y, k)
47 | 
48 | 	return d == x
49 | }
50 | 
51 | func getFloatDigit(number float64, digit int) int {
52 | 	return (int)(math.Abs(number)*math.Pow10(digit)) % 10
53 | }
54 | 
55 | func encrypt(str_dMsg string) string {
56 | 	t := 1_234_567_890
57 | 	i := 0
58 | 
59 | 	str_eMsg := ""
60 | 
61 | 	for j := 0; j < len(str_dMsg); j++ {
62 | 		x := int(str_dMsg[j] - '0')
63 | 
64 | 		k := digitKey(t, i, j)
65 | 
66 | 		y := encryptDigit(x, k)
67 | 
68 | 		str_eMsg += strconv.Itoa(y)
69 | 	}
70 | 
71 | 	return str_eMsg
72 | }
73 | 


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