A Security tool or application

I am looking for a skilled professional to develop a security tool or application that provides medium-level protection. The tool/application should be compatible with both Windows and Mac operating systems. The ideal candidate should have experience in developing security software and be knowledgeable about different security protocols. The tool/application should have the following features:

- Antivirus software
- Firewall
- Encryption software

The tool/application should be easy to use and should not affect the performance of the system. The candidate should be able to provide ongoing support and updates for the tool/application.