hello all.. i m making a server client authentication model for this i m using MessageDigest class and its MD5 method. By the help of this i am generating a random field called "key". And this key sends to the client, with username called "vinay", and ServerName.. Sent field:- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ WWW-Authenticate:: ServerName="WORKGROUP", key="0c977ebb93725e437e7d75f8adc1dc", UserName="vinay", algorithm="MD5"; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ And client should reply with ...