ADFGVX cipher: Difference between revisions
Added Go
(Added Go) |
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These should then be used to encrypt the plaintext: '''ATTACKAT1200AM''' and decrypt the resulting cipher text. Display here the results of both operations.
<br><br>
=={{header|Go}}==
{{trans|Wren}}
<lang go>package main
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"math/rand"
"sort"
"strings"
"time"
)
var adfgvx = "ADFGVX"
var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
func distinct(bs []byte) []byte {
var u []byte
for _, b := range bs {
if !bytes.Contains(u, []byte{b}) {
u = append(u, b)
}
}
return u
}
func allAsciiAlphaNum(word []byte) bool {
for _, b := range word {
if !((b >= 48 && b <= 57) || (b >= 65 && b <= 90) || (b >= 97 && b <= 122)) {
return false
}
}
return true
}
func orderKey(key string) []int {
temp := make([][2]byte, len(key))
for i := 0; i < len(key); i++ {
temp[i] = [2]byte{key[i], byte(i)}
}
sort.Slice(temp, func(i, j int) bool { return temp[i][0] < temp[j][0] })
res := make([]int, len(key))
for i := 0; i < len(key); i++ {
res[i] = int(temp[i][1])
}
return res
}
func createPolybius() []string {
temp := []byte(alphabet)
rand.Shuffle(36, func(i, j int) {
temp[i], temp[j] = temp[j], temp[i]
})
alphabet = string(temp)
fmt.Println("6 x 6 Polybius square:\n")
fmt.Println(" | A D F G V X")
fmt.Println("---------------")
p := make([]string, 6)
for i := 0; i < 6; i++ {
fmt.Printf("%c | ", adfgvx[i])
p[i] = alphabet[6*i : 6*(i+1)]
for _, c := range p[i] {
fmt.Printf("%c ", c)
}
fmt.Println()
}
return p
}
func createKey(n int) string {
if n < 7 || n > 12 {
log.Fatal("Key should be within 7 and 12 letters long.")
}
bs, err := ioutil.ReadFile("unixdict.txt")
if err != nil {
log.Fatal("Error reading file")
}
words := bytes.Split(bs, []byte{'\n'})
var candidates [][]byte
for _, word := range words {
if len(word) == n && len(distinct(word)) == n && allAsciiAlphaNum(word) {
candidates = append(candidates, word)
}
}
k := string(bytes.ToUpper(candidates[rand.Intn(len(candidates))]))
fmt.Println("\nThe key is", k)
return k
}
func encrypt(polybius []string, key, plainText string) string {
temp := ""
outer:
for _, ch := range []byte(plainText) {
for r := 0; r <= 5; r++ {
for c := 0; c <= 5; c++ {
if polybius[r][c] == ch {
temp += fmt.Sprintf("%c%c", adfgvx[r], adfgvx[c])
continue outer
}
}
}
}
colLen := len(temp) / len(key)
// all columns need to be the same length
if len(temp)%len(key) > 0 {
colLen++
}
table := make([][]string, colLen)
for i := 0; i < colLen; i++ {
table[i] = make([]string, len(key))
}
for i := 0; i < len(temp); i++ {
table[i/len(key)][i%len(key)] = string(temp[i])
}
order := orderKey(key)
cols := make([][]string, len(key))
for i := 0; i < len(key); i++ {
cols[i] = make([]string, colLen)
for j := 0; j < colLen; j++ {
cols[i][j] = table[j][order[i]]
}
}
res := make([]string, len(cols))
for i := 0; i < len(cols); i++ {
res[i] = strings.Join(cols[i], "")
}
return strings.Join(res, " ")
}
func decrypt(polybius []string, key, cipherText string) string {
colStrs := strings.Split(cipherText, " ")
// ensure all columns are same length
maxColLen := 0
for _, s := range colStrs {
if len(s) > maxColLen {
maxColLen = len(s)
}
}
cols := make([][]string, len(colStrs))
for i, s := range colStrs {
var ls []string
for _, c := range s {
ls = append(ls, string(c))
}
if len(s) < maxColLen {
cols[i] = make([]string, maxColLen)
copy(cols[i], ls)
} else {
cols[i] = ls
}
}
table := make([][]string, maxColLen)
order := orderKey(key)
for i := 0; i < maxColLen; i++ {
table[i] = make([]string, len(key))
for j := 0; j < len(key); j++ {
table[i][order[j]] = cols[j][i]
}
}
temp := ""
for i := 0; i < len(table); i++ {
temp += strings.Join(table[i], "")
}
plainText := ""
for i := 0; i < len(temp); i += 2 {
r := strings.IndexByte(adfgvx, temp[i])
c := strings.IndexByte(adfgvx, temp[i+1])
plainText = plainText + string(polybius[r][c])
}
return plainText
}
func main() {
rand.Seed(time.Now().UnixNano())
plainText := "ATTACKAT1200AM"
polybius := createPolybius()
key := createKey(9)
fmt.Println("\nPlaintext :", plainText)
cipherText := encrypt(polybius, key, plainText)
fmt.Println("\nEncrypted :", cipherText)
plainText2 := decrypt(polybius, key, cipherText)
fmt.Println("\nDecrypted :", plainText2)
}</lang>
{{out}}
Sample run:
<pre>
6 x 6 Polybius square:
| A D F G V X
---------------
A | R W H N I 7
D | 1 J O 2 P 5
F | 3 A T 4 M 9
G | D U L K V 0
V | Z B E F 6 Q
X | G Y S 8 C X
The key is EUCHARIST
Plaintext : ATTACKAT1200AM
Encrypted : FDG FGG FVDV FFX FFF FFX DDD XAF DGG
Decrypted : ATTACKAT1200AM
</pre>
=={{header|Nim}}==
| |||