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 utilizes 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 (Brunschwig, 2013).