Simple problem with encryption

I got this method that encrypts and decrypts text. All of it works fine, except when it comes to spaces. It doesn't convert the spaces correct. If you take a look at it, you might understand.

import java.util.*;

public class CustomCypher
{
	public String encryptText(String key, String text)
	{
		long finalKey = 0;
		for (int i=0; i<key.length(); i++)
		{
			long tempKey = key.charAt(i);
			tempKey *= 128;
			finalKey += tempKey;
		}
		
		Random generator = new Random(finalKey);
		String returnString = "";
		for (int i=0; i<text.length(); i++)
		{
			int temp = (int)text.charAt(i);
			temp += generator.nextInt(95);
			if (temp > 126)
			{
				temp -= 95;
			}
			returnString += (char)temp;
		}
		
		return returnString;
	}
	public String decryptText(String key, String text)
	{
		long finalKey = 0;
		for (int i=0; i<key.length(); i++)
		{
			long tempKey = key.charAt(i);
			tempKey *= 128;
			finalKey += tempKey;
		}
		
		Random generator = new Random(finalKey);
		String returnString = "";
		for (int i=0; i<text.length(); i++)
		{
			int temp = (int)text.charAt(i);
			temp -= generator.nextInt(95);
			if (temp < 36)
			{
				temp+= 95;
			}
			else if (temp > 126)
			{
				temp -= 95;
			}
			returnString += (char)temp;
		}
		
		return returnString;
	}
}

server_crash

Postaholic

2,111 posts since Jun 2004

Reputation Points: 113

Solved Threads: 20

7 Years Ago

I got this method that encrypts and decrypts text. All of it works fine, except when it comes to spaces. It doesn't convert the spaces correct. If you take a look at it, you might understand.

import java.util.*;

public class CustomCypher
{
	public String encryptText(String key, String text)
	{
		long finalKey = 0;
		for (int i=0; i<key.length(); i++)
		{
			long tempKey = key.charAt(i);
			tempKey *= 128;
			finalKey += tempKey;
		}
		
		Random generator = new Random(finalKey);
		String returnString = "";
		for (int i=0; i<text.length(); i++)
		{
			int temp = (int)text.charAt(i);
			temp += generator.nextInt(95);
			if (temp > 126)
			{
				temp -= 95;
			}
			returnString += (char)temp;
		}
		
		return returnString;
	}
	public String decryptText(String key, String text)
	{
		long finalKey = 0;
		for (int i=0; i<key.length(); i++)
		{
			long tempKey = key.charAt(i);
			tempKey *= 128;
			finalKey += tempKey;
		}
		
		Random generator = new Random(finalKey);
		String returnString = "";
		for (int i=0; i<text.length(); i++)
		{
			int temp = (int)text.charAt(i);
			temp -= generator.nextInt(95);
			if (temp < 36)
			{
				temp+= 95;
			}
			else if (temp > 126)
			{
				temp -= 95;
			}
			returnString += (char)temp;
		}
		
		return returnString;
	}
}

In the decrypt function change
if (temp < 36)
{
temp+= 95;
}
else if (temp > 126)
{
temp -= 95;
}

to
if (temp < 36)
{
temp+= 95;
}
if (temp > 126)
{
temp -= 95;
}

I think this solves the problem. All though I do not know the crypting algo and I dont understand the exact logic. But brute debugging suggests this.

aj.wh.ca

Junior Poster in Training

53 posts since Mar 2005

Reputation Points: 12

Solved Threads: 1