SHA-512 Hash In Java

• Difficulty Level : Medium
• Last Updated : 27 Sep, 2018

The SHA-2 family of cryptographic hash functions consists of six hash functions. These are:

1. SHA-224, with 224 bit hash values
2. SHA-256, with 256 bit hash values
3. SHA-384, with 384 bit hash values
4. SHA-512, with 512 bit hash values
5. SHA-512/224, with 512 bit hash values
6. SHA-512/256, with 512 bit hash values

   Among these, SHA-256 and SHA-512 are the most commonly accepted and used hash functions computed with 32-bit and 64-bit words, respectively. SHA-224 and SHA-384 are truncated versions of SHA-256 and SHA-512 respectively, computed with different initial values.

    

   To calculate cryptographic hashing value in Java, MessageDigest Class is used, under the package java.security.

   MessagDigest Class provides following cryptographic hash function to find hash value of a text as follows:

    

    

    
   • MD2
   • MD5
   • SHA-1
   • SHA-224
   • SHA-256
   • SHA-384
   • SHA-512

   These algorithms are initialized in static method called getInstance(). After selecting the algorithm the message digest value is calculated and the results is returned as byte array. BigInteger class is used, to convert the resultant byte array into its signum representation. This representation is then converted into hexadecimal format to get the expected MessageDigest.

   Examples:

   Input : hello world
   Output : 309ecc489c12d6eb4cc40f50c902f2b4d0ed77ee511a7c7a9bcd3ca86d4cd86f989dd35bc5ff499670da34255b45b0cfd830e81f605dcf7dc5542e93ae9cd76f

   Input : GeeksForGeeks
   Output : acc10c4e0b38617f59e88e49215e2e894afaee5ec948c2af6f44039f03c9fe47a9210e01d5cd926c142bdc9179c2ad30f927a8faf69421ff60a5eaddcf8cb9c

   Program: Below program shows the implementation of SHA-512 hash function:

    

    

    

   // Java program to calculate SHA-512 hash value

     

   import java.math.BigInteger;

   import java.security.MessageDigest;

   import java.security.NoSuchAlgorithmException;

     

   public class GFG {

       public static String encryptThisString(String input)

       {

           try {

               // getInstance() method is called with algorithm SHA-512

               MessageDigest md = MessageDigest.getInstance("SHA-512");

     

               // digest() method is called

               // to calculate message digest of the input string

               // returned as array of byte

               byte[] messageDigest = md.digest(input.getBytes());

     

               // Convert byte array into signum representation

               BigInteger no = new BigInteger(1, messageDigest);

     

               // Convert message digest into hex value

               String hashtext = no.toString(16);

     

               // Add preceding 0s to make it 32 bit

               while (hashtext.length() < 32) {

                   hashtext = "0" + hashtext;

               }

     

               // return the HashText

               return hashtext;

           }

     

           // For specifying wrong message digest algorithms

           catch (NoSuchAlgorithmException e) {

               throw new RuntimeException(e);

           }

       }

     

       // Driver code

       public static void main(String args[]) throws NoSuchAlgorithmException

       {

     

           System.out.println("HashCode Generated by SHA-512 for: ");

     

           String s1 = "GeeksForGeeks";

           System.out.println("\n" + s1 + " : " + encryptThisString(s1));

     

           String s2 = "hello world";

           System.out.println("\n" + s2 + " : " + encryptThisString(s2));

       }

   }

   Output:

   HashCode Generated by SHA-512 for:GeeksForGeeks : acc10c4e0b38617f59e88e49215e2e894afaee5ec948c2af6f44039f03c9fe47a9210e01d5cd926c142bdc9179c2ad30f927a8faf69421ff60a5eaddcf8cb9chello world : 309ecc489c12d6eb4cc40f50c902f2b4d0ed77ee511a7c7a9bcd3ca86d4cd86f989dd35bc5ff499670da34255b45b0cfd830e81f605dcf7dc5542e93ae9cd76f

   Application:

   • Cryptography
   • Data Integrity