title: Worked Example of Digital Signature Algorithm
body: <p>Does anybody have a DSA worked example with simple values on how to calculate r,s and verify v == r.  As this standard has been around awhile and is implemented in librarys e.g. the Java Cryptography Extension I'm finding it very hard to find an example of how the algorithm works.</p>
  
  <pre><code>Compute r=(gk mod p) mod q 
  Compute s=(k-1 * (x * r + i)) mod q 
  Verifying a signature; again i is the input, and (r,s) is the signature. 
  
  u1 = (s-1 * i) mod q 
  u2 = (s-1 * r) mod q 
  v = ((gu1 * yu2) mod p) mod q 
  If v equals r, the signature is valid.
  </code></pre>
  
  <p>Thanks,</p>