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Data Encryption and Secure Data Transmission
Understanding Data Encryption
Data encryption is a critical component in securing data transmission. It involves converting data into a coded format to prevent unauthorized access.
- Symmetric Encryption
- Asymmetric Encryption
- Hash Functions
Uses the same key for both encryption and decryption. It's fast but requires secure key distribution.
Utilizes a pair of keys - public and private. It is more secure but slower than symmetric encryption.
Transforms data into a fixed-size hash value, ensuring data integrity.
Example: Symmetric Encryption with AES
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
public class SymmetricEncryption {
public static void main(String[] args) throws Exception {
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
SecretKey secretKey = keyGen.generateKey();
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
String plainText = "SecureData";
byte[] encryptedText = cipher.doFinal(plainText.getBytes());
System.out.println(new String(encryptedText));
}
}
Symmetric Encryption with AES
This example demonstrates how to encrypt data using the AES algorithm, a popular symmetric encryption technique.
Example: Asymmetric Encryption with RSA
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import javax.crypto.Cipher;
public class AsymmetricEncryption {
public static void main(String[] args) throws Exception {
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
KeyPair pair = keyGen.generateKeyPair();
PublicKey publicKey = pair.getPublic();
PrivateKey privateKey = pair.getPrivate();
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
String plainText = "SecureData";
byte[] encryptedText = cipher.doFinal(plainText.getBytes());
System.out.println(new String(encryptedText));
}
}
Asymmetric Encryption with RSA
RSA is a widely used asymmetric encryption algorithm that uses a pair of keys for secure data transmission.
Example: Hashing with SHA-256
import java.security.MessageDigest;
public class HashingExample {
public static void main(String[] args) throws Exception {
String data = "SecureData";
MessageDigest md = MessageDigest.getInstance("SHA-256");
byte[] hash = md.digest(data.getBytes());
StringBuilder hexString = new StringBuilder();
for (byte b : hash) {
hexString.append(Integer.toHexString(0xFF & b));
}
System.out.println(hexString.toString());
}
}
Hashing with SHA-256
SHA-256 is a cryptographic hash function that ensures data integrity by producing a unique hash value for a given input.
Example: Digital Signatures
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.Signature;
public class DigitalSignatureExample {
public static void main(String[] args) throws Exception {
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
KeyPair pair = keyGen.generateKeyPair();
PrivateKey privateKey = pair.getPrivate();
Signature sign = Signature.getInstance("SHA256withDSA");
sign.initSign(privateKey);
String data = "SecureData";
sign.update(data.getBytes());
byte[] digitalSignature = sign.sign();
System.out.println(new String(digitalSignature));
}
}
Digital Signatures
Digital signatures provide data authenticity and integrity by using cryptographic algorithms to sign data.
Example: Secure Socket Layer (SSL)
// SSL example is theoretical as Java code for SSL setup is complex
// SSL/TLS is used for secure communication over a computer network
Secure Socket Layer (SSL)
SSL/TLS protocols are used to establish a secure connection between a client and server, ensuring data is transmitted securely.
Example: Transport Layer Security (TLS)
// TLS example is theoretical as Java code for TLS setup is complex
// TLS is an updated, more secure version of SSL
Transport Layer Security (TLS)
TLS is an enhanced version of SSL, providing improved security features for data transmission over networks.
