Bacon cipher: Difference between revisions

=={{header|Groovy}}==

{{trans|Java}}

<lang groovy>class BaconCipher {

private static final Map<Character, String> codes

static {

codes = new HashMap<>()

codes['a' as Character] = "AAAAA"

codes['b' as Character] = "AAAAB"

codes['c' as Character] = "AAABA"

codes['d' as Character] = "AAABB"

codes['e' as Character] = "AABAA"

codes['f' as Character] = "AABAB"

codes['g' as Character] = "AABBA"

codes['h' as Character] = "AABBB"

codes['i' as Character] = "ABAAA"

codes['j' as Character] = "ABAAB"

codes['k' as Character] = "ABABA"

codes['l' as Character] = "ABABB"

codes['m' as Character] = "ABBAA"

codes['n' as Character] = "ABBAB"

codes['o' as Character] = "ABBBA"

codes['p' as Character] = "ABBBB"

codes['q' as Character] = "BAAAA"

codes['r' as Character] = "BAAAB"

codes['s' as Character] = "BAABA"

codes['t' as Character] = "BAABB"

codes['u' as Character] = "BABAA"

codes['v' as Character] = "BABAB"

codes['w' as Character] = "BABBA"

codes['x' as Character] = "BABBB"

codes['y' as Character] = "BBAAA"

codes['z' as Character] = "BBAAB"

codes[' ' as Character] = "BBBAA"

}

private static String encode(String plainText, String message) {

String pt = plainText.toLowerCase()

StringBuilder sb = new StringBuilder()

for (char c : pt.toCharArray()) {

if (('a' as char) <= c && c <= ('z' as char)) sb.append(codes.get(c))

else sb.append(codes.get(' ' as char))

}

String et = sb.toString()

String mg = message.toLowerCase() // 'A's to be in lower case, 'B's in upper case

sb.setLength(0)

int count = 0

for (char c : mg.toCharArray()) {

if (('a' as char) <= c && c <= ('z' as char)) {

if (et.charAt(count) == ('A' as char)) sb.append(c)

else sb.append((c - 32) as char) // upper case equivalent

count++

if (count == et.length()) break

} else sb.append(c)

}

return sb.toString()

}

private static String decode(String message) {

StringBuilder sb = new StringBuilder()

for (char c : message.toCharArray()) {

if (('a' as char) <= c && c <= ('z' as char)) sb.append('A')

if (('A' as char) <= c && c <= ('Z' as char)) sb.append('B')

}

String et = sb.toString()

sb.setLength(0)

for (int i = 0; i < et.length(); i += 5) {

def maxIdx = Math.min(i + 5, et.length())

String quintet = et.substring(i, maxIdx)

Character key = codes.entrySet().stream().filter({ a -> Objects.equals(a.getValue(), quintet) }).findFirst().map({ e -> e.getKey() }).orElse(null) as Character

sb.append(key)

}

return sb.toString()

}

static void main(String[] args) {

String plainText = "the quick brown fox jumps over the lazy dog"

String message = "bacon's cipher is a method of steganography created by francis bacon. " +

"this task is to implement a program for encryption and decryption of " +

"plaintext using the simple alphabet of the baconian cipher or some " +

"other kind of representation of this alphabet (make anything signify anything). " +

"the baconian alphabet may optionally be extended to encode all lower " +

"case characters individually and/or adding a few punctuation characters " +

"such as the space."

String cipherText = encode(plainText, message)

System.out.printf("Cipher text ->\n\n%s\n", cipherText)

String decodedText = decode(cipherText)

System.out.printf("\nHidden text ->\n\n%s\n", decodedText)

}

}</lang>

{{out}}

<pre>Cipher text ->

BacON's cIPHer Is a METhoD of stEgAnogRaphy crEatEd By FRAncis baCOn. thIs TASk Is TO imPLeMENT a proGrAm FOR eNcRYPTIOn anD deCRyPtioN Of plAINTExt UsING the SIMpLe AlPhaBet Of thE BAConIan CIphER Or sOme OTHer kInD Of reprESenTATion OF This alPHaBET (makE An

Hidden text ->

the quick brown fox jumps over the lazy dog</pre>