The employment contract should contain terms that prohibit employees from using or disclosing your confidential information outside the scope of employment as well as prohibit them from using or disclosing confidential information learned during previous jobs. Employees should be provided with training on what you consider confidential and what is expected of them in maintaining the confidentiality of your information.
Remember, employees are the biggest source of trade secret loss of companies.
Whenever an employee changes jobs, it is unavoidable that some of the employee’s previously acquired knowledge will be made available to the new employer. Contractual terms that prohibit post- employment competition or solicitation of customers may or may not be legal depending on the jurisdiction. The advice of an attorney should be sought.
Remember to enter into non-disclosure agreements with all those you engage with in the course of your business and to whom you disclose your confidential business information.