SHA-1 Hash

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SHA-1 Hash

SHA-1 Hash

SHA-1 or Secure Hash Algorithm 1 is a cryptographic hash function which takes an input and produces a 160-bit (20-byte) hash value. This hash value is known as a message digest. This message digest is usually then rendered as a hexadecimal number which is 40 digits long. It is a U.S. Federal Information Processing Standard and was designed by the United States National Security Agency.

SHA-1 is now considered insecure since 2005. Major tech giants browsers like Microsoft, Google, Apple and Mozilla have stopped accepting SHA-1 SSL certificates by 2017.

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

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

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


Input : Hello Everyone
Output : 2aae6c35c94fcfb415dbe95f408b9ce91ee846ed

Input :
Output : addf120b430021c36c232c99ef8d926aea2acd6b

Below program shows the implementation of SHA-1 hash in Java.

// Java program to calculate SHA-1 hash value

import java.math.BigInteger;

public class Prutor {
public static String encryptThisString(String input)
try {
// getInstance() method is called with algorithm SHA-1
MessageDigest md = MessageDigest.getInstance("SHA-1");

// 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

System.out.println("HashCode Generated by SHA-1 for: ");

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

String s2 = "Hello Everyone";
System.out.println("n" + s2 + " : " + encryptThisString(s2));
Result :
HashCode Generated by SHA-1 for: : addf120b430021c36c232c99ef8d926aea2acd6b

Hello Everyone : 2aae6c35c94fcfb415dbe95f408b9ce91ee846ed

Data Integrity

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', { 'anonymize_ip': true });