Physical methods

Keep track of documents. Put procedures in place for retention and destruction
Limit disclosure on certain types of information with a 'Need to Know' policy
Mark confidential documents as 'CONFIDENTIAL' documents
* Too many documents marked as confidential may have an adverse effect causing the actual confidentiality to be lost. If normal everyday documents are marked as such, people will learn to disregard or even ignore the notice.
Enforce standards to keep certain information under lock and key
Regularly change keys to these areas
Use access screening and visitor control policies
For information stored on computers use software barriers, passwords and self-destruct disks

Employee Contracts

The use of contractual barriers can impose on people an obligation of confidentiality. This may be due to an express or implied term within the contract.
A contract may be entirely oral, entirely written or only part written, but will be binding where one party agrees to disclose information and the other agrees to treat it as confidential. If the contract is wholly in writing, it is easier to prove what has been agreed, and if well written, may reduce to risk of misunderstandings.

An implied contract term will only be enforced by law if the court finds that the parties intended for the term to be included in the contract at the time of creating the agreement. It is clearly better to expressly deal with confidentiality issues, especially when partaking in sensitive or potentially sensitive negotiations. Such negotiations may involve revealing technical information or prototypes to customers or manufacturers for purposes such as evaluation.

Types of confidential information written into contracts include:
Customer information: lists, contact names, pricing information, requirements, payment history.
Financial information: performance history, strong and weak points
Plans: marketing, target markets, new products/services, and inventions.
Products/Services: processes, formulas.
Others: management problems, business allies

Employment contracts do, however, cause problems, as the contractual obligation of confidence is subject to the fact that an employee is, after the termination of his contract of employment, free to use his general knowledge and skill either for his own benefit or for the benefit of others. However, the employer will want to stop any information being given to the competitor which may increase competition or damage business. In employment cases the implied obligation of confidence is to act in good faith and fidelity, which every employee owes to his employer. This obligation exists during the term of the contract, but, also continues once the employee terminates employment and as long as the information remains confidential.

The obligation of fidelity owed by an employee to his employer, whilst employed, can be expressed as follows:
An employee is bound not to disclose or use confidential information which he receives in the course of his employment for purposes which are against the interests of his employer.
An employee must not use information for personal benefit or work for any of his competitors.
The employee is bound to disclose to his employer any valuable information which he receives in his capacity as an employee and which is unknown to his employer, and this will include any confidential information which would further his employer's trade.
After employment has terminated the employee's implied duty of good faith continues and he will still be required to keep confidential those secrets which he learnt during his former employment

In order to determine whether information could be classified as so confidential that an employee should not be allowed to use or disclose it for the benefit of a subsequent employer it is necessary to consider all the circumstances of the particular case.
The following are among those to which attention must be paid:
the nature of employment: if the employee regularly handled confidential information then he or she can be expected to recognise confidential information more readily than other employees.
The nature of the information: in order to be protected the information must be of a highly confidential nature.
Whether the employer pointed out to the employee the confidentiality of the information.
Whether the relevant information can be easily distinguished from other information which the employee uses

The result of this is that if information is not categorised as confidential under those criteria then it forms part of the employee's general knowledge and skill.

It is up to you as the employer to safeguard yourself by a variety of approaches, physically, contractually and by applying exit interview strategies to ensure employees do not take and use “secrets” against you. The common law limits protection to trade secrets and therefore makes it more difficult for a business to protect its confidential information when an employee leaves, unless there are specific clauses in the employment contract, which clearly cover specific information assets.