Question

I want to compute Hash of a String, but the Hash value should be a number (long or integer).

In other words I want to compute integer hash of a string.
Collusion resistance in not the concern.

Is there an way to convert MessageDigest of SHA-256 to a number.

I am using Java to accomplish this.

Answer 1

A Sha Hash has 256 Bits e.g.

"364b7e70a9966ef7686ab814958cd0017b7f19147a257d40603d4a1307662b42"

this will exceed the range of long and integer.
You could use new BigInteger( hash, 16 ); for a decimal representation.

public static void main(String[] args) throws NoSuchAlgorithmException {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        digest.update("string".getBytes() );
        byte[] hash = digest.digest();
        BigInteger bi = new BigInteger( hash );
        System.out.println( "hex:" + bi.toString(16) + "\r\ndec:" + bi.toString() );
    }