Encrypted data in 128, you can customize the symbol table and use your favorite symbols for encryption
The code copy is as follows:
package com.wmly.enc;
import java.util.HashMap;
/**
* 128-bit encryption and decryption, one symbol can represent 7 bits
* You can customize the symbol table, but the symbol cannot be repeated
*/
public class MyBASE128 {
public static final char[] symbolTable = new char[128];
public static final HashMap<Character, Integer> indexTable = new HashMap<>(128);
static {
int i = 0;
for (int j = 0; j < 128; j++) {
//symbolTable[j] = (char) j;
if('A' <= j && j <= 'Z'
|| 'a' <= j && j <= 'z'
|| '0' <= j && j <= '9') {
symbolTable[i++] = (char) j;
}
}
for (char c : "This is written by Chinese people [Bie Si Yao Aifa] codec program & has a unique custom symbol table | But cloth can use duplicate words, sweat (it is still 12 knowledge*. #). Come on for us, dear! ".toCharArray()) {
symbolTable[i++] = c;
}
checkTable();
for (int j = 0; j < 128; j++) {
indexTable.put(symbolTable[j], j);
}
}
private static void checkTable() throws Error {
if(symbolTable[127] == 0) {
throw new Error("The symbol table length is incorrect!");
}
for (char a : symbolTable) {
int count = 0;
for (char b : symbolTable) {
if(a == b) {
count++;
}
}
if(count > 2) {
throw new Error("The symbol table has repeated symbols!");
}
}
}
public String encode(byte[] data) {
if(data == null || data.length == 0) {
return new String();
}
StringBuilder result = new StringBuilder();
int tail = 0;
for (int i = 0; i < data.length; i++) {
int mov = (i % 7 + 1);
int curr = 0xFF & data[i];
int code = tail + (curr >> mov);
result.append(symbolTable[code]);
tail = (0xFF & (curr << (8 - mov))) >> 1;
if(mov == 7) {
result.append(symbolTable[tail]);
tail = 0;
}
}
result.append(symbolTable[tail]);
return result.toString();
}
public byte[] decode(String base128) {
if(base128 == null || base128.length() == 0) {
return new byte[] { };
}
int length = (int) Math.floor(base128.length() * 0.875);
byte[] result = new byte[length];
int idx = 0;
int head = indexTable.get(base128.charAt(0)) << 1;
for (int i = 1; i < base128.length();) {
int mod = i % 8;
int code = indexTable.get(base128.charAt(i++));
result[idx++] = (byte) (0xFF & (head + (code >> (7 - mod))));
if(mod == 7) {
head = 0xFF & (indexTable.get(base128.charAt(i++)) << 1);
} else {
head = 0xFF & (code << (mod + 1));
}
}
return result;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// //////////////
public static void main(String[] args) {
MyBASE128 base128 = new MyBASE128();
test(base128);
String txt = "This is my encryption and decryption test";
String enc = base128.encode(txt.getBytes());
System.out.println(enc);
System.out.println("----------------");
System.out.println(new String(base128.decode(enc)));
}
private static void test(MyBASE128 base128) {
for (int i = 0; i < 10000; i++) {
String r = randomData();
String d = new String(base128.decode(base128.encode(r.getBytes())));
if(!r.equals(d)) {
//d = new String(base128.decode(base128.encode(r.getBytes())));
System.out.println("Encryption failed!: " + r);
}
}
}
private static String randomData() {
String textString = "I'm tired of coffee maker and wear a wig/n/r-";
int start = random(0, textString.length() - 3);
int end = random(start + 1, textString.length() - 1);
return textString.substring(start, end);
}
private static int random(int i, int j) {
return (int) Math.ceil(Math.random()*(ji)+i);
}
}