Background:

For background on hashing and message digests see this

Instructions:

The ComboBox shows all the message digest algorithms available from this version of Java. Choose one. Click the Reset button to reset the digest. Click the "Update" button to update. The latest digest is shown between the two dashed lines. The previous digest is shown below the bottomost dashed line.

Try this:

Enter a line of text in the field labeled "text:". Choose an algorithm. Click "Use Text" and "Reset". Copy the numbers. Change one character in the text line then repeat for the same algorithm. How much of the digest is different?