Encrypting a vote with a servers public key...HELP!

Hey, I really need some help( online voting application)....what I want to do it allow a voter to be able to submit a ballot(vote) via servlets, they encrypt the ballot with the servers public key and then the ballot is stored in a database, where at another time the administrator may decrypt the ballot(s) using the servers private key. I have already sorted the voters authentication(MD5), and at the moment the servlet submits the ballot in an unencrypted form....so I just need a little help from here. I enclose my code and I would be truly grateful of someone could give me a hand.
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.* ;
public class CastVote extends HttpServlet{
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException,IOException{
try {
String jmulligan= request.getParameter("jmulligan");
String pkelly=request.getParameter("pkelly");
String mjones=request.getParameter("mjones");
response.setContentType("text/html");
PrintWriter out=response.getWriter();
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection ("jdbc:odbc:evoting");
Statement stmt = con.createStatement();
stmt.executeUpdate(
"INSERT INTO Ballot (JMulligan, PKelly, MJones)"
+ "VALUES ('"+jmulligan+"','"+pkelly+"','"+mjones+"') ");
stmt.close();
out.println("<HTML>\n"+
"<HEAD><TITLE>EVoting</TITLE></HEAD>\n"+
"<BODY BGCOLOR=\"127734\">\n"+
"<H1>Your Ballot has been entered as follows</H1>\n"+
"<H1>J Mulligan got "+ jmulligan +"</H1>\n"+
"<H1> M Jones got "+ mjones +"</H1>\n"+
"<H1> P Kelly got "+ pkelly +"</H1>\n"+
"</BODY></HTML>");
catch( Exception e ) {
System.out.println(e.getMessage());
e.printStackTrace();
thanks
Jacinta
PS I have ssl configured, with a self signed cert.

Hey!
I am also in the middle of doing an en=voting application as part of my thesis! Its interesting to see the way other people do the voting. Well, my experience so far is that I cannot get public/private key encryption to work. I have posted many topics on this forum regarding it and the reason it wont work is that the ballot that I am trying to enctypt is too large for the ballot object . I used the RSA algoithm and it wasn't able to handle my large object. So instead I have just used a symmetric algorithm and that works fine. I think its the DES algorithm. The only problem with this is that you are using the same key to encrypt and decrypt the ballot. I dont think this is secure. It has been reccomended to me that I use this symmetric algorithm as it is, but that I then use public/private key to encrypt the symmetric key! I still have a problem with this because if the key is still encrypted with public key, the user must have acces to the private key to decrypt the symmetric key to decryt the ballot. See where I'm going?
I would love to know of an asymmetric algorithm that can encrypt large objects. That would solve the whole security issue. I will post a replyhere if I find out the answer.
By the way, how is your project going?
All the best,
Chris Moltisanti

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Encrypting with an RSA Public Key

Hi everyone. I'm trying to encrypt some characters with an already generated RSA public key. Can anybody help with a SUN provider sample script?
Thanx

First of all RSA cipher is not suitable for encription of data more then one block (about 80 bytes for the OAEP mode), so it is paractically only good for the secret key wrapping (like Blowfish or DES) and second thing is that SUN JCE provider doesn't include RSA cipher implementation.

Can I encrypt a string with RSA encryption using DBMS_CRYPTO?

We have an web application that does a redirect thru a database package to a 3rd party site. They would like us to encrypt the querystring that is passed using RSA encryption. The example that they've given us (below) uses the RSA cryptographic service available in .NET. Is it possible to do this using DBMS_CRYPTO or some other method in Oracle?
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2.1 Initialize Service
The RSA cryptographic service must be initialized with the provided public key. Below is sample code that can be used to initialize the service using the public key
C#
private void InitializeRSA( string keyFileName )
CspParameters cspParams = new CspParameters( );
cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
m_sp = new RSACryptoServiceProvider( cspParams );
//Load the public key from the supplied XML file
StreamReader reader = new StreamReader( keyFileName );
string data = reader.ReadToEnd( );
//Initializes the public key
m_sp.FromXmlString( data );
2.2 Encryption method
Create a method that will encrypt a string using the cryptographic service that was initialized in step 2.1. The encryption method should convert the encryption method to Base64 to avoid special characters from being passed in the URL. Below is sample code that uses the method created in step 2.1 that can be used to encrypt a string.
C#
private string RSAEncrypt( string plainText )
ASCIIEncoding enc = new ASCIIEncoding( );
int numOfChars = enc.GetByteCount( plainText );
byte[ ] tempArray = enc.GetBytes( plainText );
byte[ ] result = m_sp.Encrypt( tempArray, false );
//Use Base64 encoding since the encrypted string will be used in an URL
return Convert.ToBase64String( result );
2.3 Generate URL
The query string must contain the necessary data elements configured for you school in Step 1. This will always include the Client Number and the Student ID of the student clicking on the link.
1.     Build the query string with Client Number and Student ID
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string queryString = “schoolId=1234&studentId=1234”;
The StudentCenter website will validate that the query string was generated within 3 minutes of the request being received on our server. A time stamp in UTC universal time (to prevent time zone inconsistencies) will need to be attached to the query string.
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C#
string rsa = RSAEncrypt(querystring);
string eqs = Server.UrlEncode(rsa);
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C#
string url = “https://studentcenter.uhcsr.com/custom.aspx?eqs=” + eqs

The documentation lists all the encyrption types:
http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_crypto.htm#ARPLS664

What is the probability to get the same public key twice?

when I encrypt a message using somebody's public key, what are the chances other person has generated the same key independently? Is it safe to identify a user with its public key?

The key pair (public, private key) is generated by choosing random probably prime numbers using a pseudo-random number generator.
The quality of the pseudo-random number generator determines the probability of having two people with the same public-private key pair. Usually pseudo-random number generators (like the JCE SecureRandom) use some entropy sources, like the real-time clock, the time elapsed between keystrokes, bits of the screen, etc.)
If you use true hardware random number generators (like the used in crypto hardware like RSA smartcards and HSM (Hardware Security Modules), or the hardware RNG available in some Intel chipsets for the Pentium !!! and 4), you will have a probability much closer to the minimum theoretical probability.
Use hardware random number generators and crypto hardware if you really are concerned about the probability of having matching keypairs.

Encrypt data with public key?

I am trying to find a class that support encryption with PublicKey.
In the class Signature there is a method "initSign" that takes a PrivateKey as argument, but that is used for signing certificates.
What I am looking for is to make A encrypt some data with B' public key that B can decrypt with its private key...is there any class for this scenario?

You might want to check out these, if you haven't already:
http://java.sun.com/j2se/1.5.0/docs/guide/security/CryptoSpec.html
http://java.sun.com/j2se/1.5.0/docs/guide/security/jce/JCERefGuide.html
http://java.sun.com/j2se/1.5.0/docs/api/javax/crypto/package-summary.html
http://java.sun.com/j2se/1.5.0/docs/api/javax/crypto/interfaces/package-summary.html
http://java.sun.com/j2se/1.5.0/docs/api/javax/crypto/spec/package-summary.html

How encrypt msg with Public Key ?

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Allow privilleged users to enter into EXEC mode on login not working with public keys

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I have recently updated one of my Cisco ASA to v9.2(1) and noticed a function to get the perform authorization for exec shell access can do a auto-enable when logging in from ssh.
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[email protected]
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I can�t decrypt a text encrypted (using RSA) with keys on smartcard.

I use a Cyberflex Access e-gate smartcard and I can encrypt and decrypt any text on the card but if I encrypt a text outside using the exported public key, card is not able to decrypt the message.
On the card side:
�
RSAPrivateCrtKey privateKey;
RSAPublicKey publicKey;
Cipher cipherRSA;
�
private MyIdentity (byte buffer[], short offset, byte length){
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        publicKey = (RSAPublicKey) kp.getPublic();
        cipherRSA = Cipher.getInstance(Cipher.ALG_RSA_PKCS1, false);
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            register();
        } else {
            register(buffer, (short)(offset+1) ,(byte)(buffer[offset]));
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             // at offset 0 send 128 byte of data in the buffer
             apdu.sendBytesLong(apduBuffer, (short)APDUDATA, (short)outbytes);
        } else {
            ISOException.throwIt (ISO7816.SW_SECURITY_STATUS_NOT_SATISFIED);
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        byte apduBuffer[] = apdu.getBuffer();
         short byteRead = (short)(apdu.setIncomingAndReceive());
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          cipherRSA.doFinal(apduBuffer,(short)APDUDATA, byteRead, apduBuffer, (short)APDUDATA);
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        apdu.sendBytesLong(apduBuffer, (short)APDUDATA, byteRead);
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public void getPublicKey () {
        int CLA, INS, P1, P2;
        int iArray[] = new int[0];
        short sArray[] = new short[0];
        String ss = new String("");
        String s;
        byte [] sBytes = null;
        byte [] myModulus = new byte[128];
        byte [] myExponent = new byte[3];
        try     {
            CLA = 0x68;
            INS = 0x78;
            P1 = 0;
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                    System.out.println("Wrong PIN");
                } else {
                    s = iopCard.GetErrorMessage();
                    System.out.println("SendCardAPDU: " + s);
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                System.out.println("Getting Public Key...");
                if (sArray != null) {
                    sBytes = new byte[sArray.length];
                    for (int i = 0; i < sArray.length; i++) {
                        sBytes[i] = (byte)sArray;
ss = new String(sBytes);
System.out.println ("------ BEGIN PUBLIC KEY -------------------");
for (int i=0; i < sArray.length; i++){
System.out.print(Integer.toHexString(ss.charAt(i)).toUpperCase());
System.out.println ();
System.out.println ("------ END PUBLIC KEY -------------------");
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System.out.println("Nothing.");
} catch (slbException b) {
s = b.getMessage();
System.out.println("Validate error: " + s);
for (int i=0; i<128; i++){
myModulus[i] = (byte) sArray[i];
for (int i=0; i<3; i++){
myExponent[i] = (byte) sArray[128+i];
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BigInteger exponent = new BigInteger ("65537"); // there is a well-known bug in getExponent
RSAPublicKeySpec keySpec = new RSAPublicKeySpec(modulus, exponent);
KeyFactory keyFactory =null;
try {
keyFactory = KeyFactory.getInstance("RSA");
publicKey = keyFactory.generatePublic(keySpec);
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System.out.println(e.getMessage ());
} catch (InvalidKeySpecException e) {
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System.out.println("------------------ BEGIN ------------------");
ss = new String(publicKey.getEncoded());
for (int i=0; i < publicKey.getEncoded().length; i++){
System.out.print(Integer.toHexString(ss.charAt(i)).toUpperCase());
System.out.println ();
System.out.println("------------------ END ------------------");
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try {
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FileWriter fw = new FileWriter("public_raw.txt");
for (int i=0; i < publicKey.getEncoded().length; i++){
fw.write(Integer.toHexString(ss.charAt(i)).toUpperCase());
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byte resultado[] = new byte[256];
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try {
cipherRSA.init(Cipher.ENCRYPT_MODE, publicKey);
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System.out.println(e.getMessage());
} catch (BadPaddingException e) {
System.out.println(e.getMessage());
} catch (IllegalBlockSizeException e) {
System.out.println(e.getMessage());
String ss = new String (resultado);
System.out.println("------------------ BEGIN 4 ------------------");
for (int i=0; i < resultado.length; i++){
System.out.print(Integer.toHexString(ss.charAt(i)).toUpperCase());
System.out.println ();
System.out.println("------------------ END 4 ------------------");
Another question is that I don�t understand why I get a constant length string when I encrypt a text on the card and variable length string when I encrypt off the card

I thought that exponent was 3 bytes long...
On the card I have the following code:
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            byte apduBuffer[] = apdu.getBuffer();
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             apdu.setOutgoing();
             // indicate the number of bytes in the data field
             apdu.setOutgoingLength((short)bytesExp);
             // at offset 0 send 128 byte of data in the buffer
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    }And if I don't send an APDU with length expected, I get the exception 6C03 (Correct Expected Length (Le) = 0x6C00) so I send APDU with 03 length and I receive the exponent. The problem is that there is a well know bug in getExponent and it returns 00 00 00... so I set it up to 65537 outside the card.

Encrypt/Decrypt data, multiple public keys using Bouncy castle api?

Hi all.
I need to implement encrypt/decrypt functionality of some data with many public keys using bouncy castle api and EnvelopedData class in java 1.4 SE.
Could someone give me examples how to do it. I searched whole the internet and i could not find simple example.

Hi thanks very much.
I had a quick look at the examples. I will see if they could help me.
Here is more specific what i want:
Encrypt data with multiple public keys that are kept in .pkcs12 file.
And decrypt the data using coresponding private key after that.
I must use bouncy castle api for java 1.4 se.
Best regards
Edited by: menchev on Nov 13, 2008 8:26 AM

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What you're really asking for is to do something with the data that only the owner of the Private Key can use. What you should be looking at is encryption with the Public Key and not Signing with the Public Key. You will find many examples on this forum, in the JCE web-pages at Sun and in David Hook's Book "Beginning Cryptography in Java".

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I'm working on my thesis,and my prof. told me that I have to sign a
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How do I create a digital signature of a java object using a Public Key??Well as my fellow poster said it makes no sense siging (Encrypting) an Object using a Public Key as it would be available for access.
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http://www.unix.org.ua/orelly/java-ent/security/ch12_01.htm
http://www.developer.com/java/other/article.php/630851
http://mindprod.com/jgloss/digitalsignatures.html
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Hi,
I have one public key (abc.cer) which is given by provider. I have to send encrypted message to Provider using public key. How to achieve it in OSB??
Thanx
Edited by: Vinit Ahuja on Jun 16, 2011 3:17 AM

These are the steps needed to accomplish this:
1. Import the public certificate in the TrustStore of the OSB Weblogic Server.
2. Export the public certificate in PEM format. (This will be needed to embed in the custom ws policy)
3. Create a custom WS policy, with the necessary encryption configuration information. I have placed a sample WS - Policy that I have used @ http://dl.dropbox.com/u/19901533/Sample_Custom_WSPolicy_Encryption.doc for your reference.
Use a unique value for the wsu:Id in the policy.
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Encrypting a vote with a servers public key...HELP!

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