title: Simple (to code) secure hash function
body: <p>I need a secure (cryptographic) hash function with the following properties:</p>
  
  <ol>
  <li>Can be coded in as few lines as possible (in R5RS Scheme). Hopefully under 50.</li>
  <li>Memory and CPU performance within reason for password-length data. (e.g. it does not have to be super efficient or create hashes for millions of bytes of data)</li>
  </ol>
  
  <p>Most secure hash functions I can find are designed with speed/memory efficiency in mind and are complex to code as a result.</p>
  
  <p>The current candidate is Mash-1 (or Mash-2):
  <a href="http://books.google.ca/books?id=nSzoG72E93MC&amp;lpg=PA381&amp;ots=MuClx9pH8L&amp;dq=mash-2%20algorithm&amp;pg=PA352#v=onepage&amp;q=&amp;f=false" rel="noreferrer">Handbook of applied cryptography. Google Books</a> </p>
  
  <p>Thanks.</p>
  
  <p>Edit: 
  Thank you all for your answers so far. Please forgive me if the following comes off as rude, I just want to be clear. Please trust me that I have done my homework and considered the "standard" options. I know the easiest thing to do is use one of those, but that's not what I'm looking for.</p>
  
  <p>The single question I am trying to answer is:
  What cryptographically secure hash algorithm can be implemented in the smallest amount of "readable" code?  </p>
  
  <p>I have already posted the best candidate I could find. Any suggestions about something simpler, or commentary about Mash-1/2 would be most helpful.</p>