If your database is stolen, the thief won't have your users' plaintext passwords, only the hashes.

So, the thief won't be able to try to use that password in another system (as many users use the same password everywhere, this would be dangerous).

## Install `passlib`

PassLib is a great Python package to handle password hashes.

It supports many secure hashing algorithms and utilities to work with them.

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/**
 * An abstract implementation of {@link Hasher}, which only requires subtypes to implement {@link
 * #putByte}. Subtypes may provide more efficient implementations, however.
 *
 * @author Dimitris Andreou
 */
@ElementTypesAreNonnullByDefault
abstract class AbstractHasher implements Hasher {
  @Override
  @CanIgnoreReturnValue
  public final Hasher putBoolean(boolean b) {
    return putByte(b ? (byte) 1 : (byte) 0);

  private final ByteBuffer scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN);

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

  /** Updates this hasher with the given bytes. */
  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */

    hasher.putShort((short) 0x0201);
    hasher.assertBytes(new byte[] {1, 2});
  }

  public void testInt() {
    TestHasher hasher = new TestHasher();
    hasher.putInt(0x04030201);
    hasher.assertBytes(new byte[] {1, 2, 3, 4});
  }

  public void testLong() {
    TestHasher hasher = new TestHasher();
    hasher.putLong(0x0807060504030201L);
    hasher.assertBytes(new byte[] {1, 2, 3, 4, 5, 6, 7, 8});

    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher.putBytes(new byte[] {0x01, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00});
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher.putLong(0x0000000001000101L);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher

    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher.putBytes(new byte[] {0x01, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00});
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher.putLong(0x0000000001000101L);
    assertEquals(hashCode, hasher.hash().asLong());

    hasher = HASH_FN.newHasher();
    hasher

  private final ByteBuffer scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN);

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

  /** Updates this hasher with the given bytes. */
  protected void update(byte[] b) {
    update(b, 0, b.length);
  }

  /** Updates this hasher with {@code len} bytes starting at {@code off} in the given buffer. */

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        .isEqualTo(InetAddresses.forString("0.0.0.0"));

    // test compat address (should be hashed)
    assertThat(InetAddresses.getCoercedIPv4Address(InetAddresses.forString("::1.2.3.4")))
        .isNotEqualTo(InetAddresses.forString("1.2.3.4"));

    // test 6to4 address (should be hashed)
    assertThat(InetAddresses.getCoercedIPv4Address(InetAddresses.forString("2002:0102:0304::1")))