Algorithms required

I need to develop a web application using java
need to develop the following modules in that
1>Registration
2>Email generation
3>Discussion Forum
4>Downloading Documents
5>Recording Customer Complaints

I need to develop these modules based on some specific algorithms that are available like SHA1 for password encryption.
any help is appreciated :)

http://www.javaprogrammingforums.com...e-posting.html

I suggest you ask a more specific question in a more appropriate sub-forum here. What have you done? Where are you stuck? I recommend you read the link in my signature on asking questions the smart way.