Someone...please reply!!!!...its urgent!

Question

Hi,
I need to send in some values from an applet via a socket connection to the server. These values need to encrypted and have to be decrypted on the server side. Can anyone suggest me a method to do it. Or show me some example code.
I think we can use the cipherInputStream...but am not sure with the way to use it. I plan to do the encryption using one of the symmetric key encryption standards. Please help.
Thanks,
Grandhirs.

Answer 1

Hi!
I have just learn Cryptography, i think, we should write a pair of program inorder to encrypt and decrypt message sent. Following my code:
private static String encode(byte[] raw) {
StringBuffer encoded = new StringBuffer();
for (int i = 0; i < raw.length; i += 3) {
encoded.append(encodeBlock(raw, i));
return encoded.toString();
private static char[] encodeBlock(byte[] raw, int offset) {
int block = 0;
int slack = raw.length - offset - 1;
int end = (slack >= 2) ? 2 : slack;
for (int i = 0; i <= end; i++) {
byte b = raw[offset + i];
int neuter = (b < 0) ? b + 256 : b;
block += neuter << (8 * (2 - i));
char[] base64 = new char[4];
for (int i = 0; i < 4; i++) {
int sixbit = (block >>> (6 * (3 - i))) & 0x3f;
base64[i] = getChar(sixbit);
if (slack < 1) base64[2] = '=';
if (slack < 2) base64[3] = '=';
return base64;
private static char getChar(int sixBit) {
if (sixBit >= 0 && sixBit <= 25)
return (char)('A' + sixBit);
if (sixBit >= 26 && sixBit <= 51)
return (char)('a' + (sixBit - 26));
if (sixBit >= 52 && sixBit <= 61)
return (char)('0' + (sixBit - 52));
if (sixBit == 62) return '+';
if (sixBit == 63) return '/';
return '?';
public static byte[] decode(String base64) {
int pad = 0;
for (int i = base64.length() - 1; base64.charAt(i) == '='; i--)
pad++;
int length = base64.length()*6/8 - pad;
byte[] raw = new byte[length];
int rawIndex = 0;
for (int i = 0; i < base64.length(); i += 4) {
int block = (getValue(base64.charAt(i)) << 18) + (getValue(base64.charAt(i + 1)) << 12) + (getValue(base64.charAt(
i + 2)) << 6) + (getValue(base64.charAt(i + 3)));
for (int j = 0; j < 3 && rawIndex + j < raw.length; j++)
raw[rawIndex + j] = (byte)((block >> (8*(2 - j))) & 0xff);
rawIndex += 3;
return raw;
protected static int getValue(char c) {
if (c >= 'A' && c <= 'Z')
return c - 'A';
if (c >= 'a' && c <= 'z')
return c - 'a' + 26;
if (c >= '0' && c <= '9')
return c - '0' + 52;
if (c == '+')
return 62;
if (c == '/')
return 63;
if (c == '=')
return 0;
return -1;
I think You should use MD5 to hash message before encrypting. I'm very glad to join hands. Have a good time!