ABC Company  is to develop a secure message and file exchange application to enable  its remote teams to collaborate securely. The company uses a PKI as part  of its cryptosystem where each employee has its own public/private key  pair. The public keys are stored on a local key server. Files could  range from small ones to very large multimedia files (e.g. video  presentations). Messages exchanged through the system are of a short  length and a high sensitivity.
 To complete this Assignment:
 Analyse how ABC Company utilises a PKI. Recommend a cryptosystem for the  company and explain your recommendation. Identify the weakest links in  the system. Recommend solutions for those weak links and explain how  your solutions address the problems. Evaluate the applicability of the  Enigmail add-ons for Thunderbird as a  preferred choice, compared with  the burden of developing a new system