Programming Tips - Java: Make a SHA-3 hash (digest)

Date: 2025aug21 Update: 2025oct11 Language: Java Q. Java: Make a SHA-3 hash (digest) A. Here is a full example:
import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; class Demo { public static String toHexString(final byte[] ba) { final StringBuilder sb = new StringBuilder(); for(int i = 0; i < ba.length; i++) { sb.append(String.format("%02x", ba[i])); } return sb.toString(); } public static String makeSha3(final String thingOne, final String thingTwo) { MessageDigest md; try { md = MessageDigest.getInstance("SHA3-256"); // Also SHA3-224, SHA3-384 and SHA3-512 } catch (NoSuchAlgorithmException ex) { // Depends on your Java version if this happens return ""; } md.update(thingOne.getBytes()); md.update(thingTwo.getBytes()); final byte byteData[] = md.digest(); return toHexString(byteData); } public static final void main(String[] args) { String sum = makeSha3("hello", "world"); System.out.println("sha3=" + sum); } }
Output:
sha3=92dad9443e4dd6d70a7f11872101ebff87e21798e4fbb26fa4bf590eb440e71b