How can I be sure that the contents of my documents will not be disclosed to anyone else by my translator?

If you are planning to outsource the translation work to a reputable company then you should not be worried about risk related with disclosure of information as you should only search a company who is reputed one and has implemented and maintains a comprehensive information security management system certified from the international information security standard, ISO27001. Mostly, these reputed companies established processes for handling confidential information undergo rigorous independent auditing from external source and these companies strive to continuously improve their data protection technology by conducting regular risk assessment, risk mitigation and evaluation processes. You can also verify to check whether the company's ISO certification is available ,which mostly uploaded on the company website.

If you have hired a person for the same task then you can consult a Legal person who then bound the second party in an agreement or contract through which you can cope up with the desired risk of disclosing information. Another way is to draft an agreement or a contract by yourself and have it vetted from a reputed Legal Person or Firm.

Best Regards,

Ali 

A non-disclosure agreement should be obtained from the translation firm or person, and if there is a breach of such an agreement and a source of the leak of information is evidently traced to the translation firm or person then the said firm or person is liable to pay liquidate damages and also be blacklisted for future work.

The best way to do so that your files will not be seen by others is to use a codes or numbers as filenames. Anyone who wants to check your files will have a hardtime to find what they wants. However, you should have a list of these codes or numbers for yourself. Or if you don't trust anyone, then make sure that nobody will use your computer by putting a password on it.

Confidential documents should be properly kept and tag as confidential file. Disclosure confidential file must be shredded right away if necessary. The Person assign in this category must have the ability to know the importance of documents and have sense of confidentiality or Trustworthy. 

First belive in the person to whom we are assigning the job.

Faith depends on 

dedication, honesty and hardwork and commitment.

Only a TRUST, ......That is what is called as"TRUST" & have to be Honest in our Job

It is quite difficult to trust any person nowadays and the more the sensitive the information is or documents the more tight the security has to be less it fall to the wrong hands. The only way you can ensure that the info remains undisclosed to other persons by your translator is to let him/her sign agreement of confidentiality. That way you can be rest assured if the information leaks someone will have to answer for it.

Only trustworthy on any orginization is the best thing that any one could not use it in rude manner.

It depends on company policy regarding privacy of clients information with regard to documentation.You can know how the company can handle the documentation process and hence your information from the beginning e.g how the company or secretary receives you in your first contact with the company.If your first conversation is treated to be private and personalized then rest assured of the safety of your documents. 

Strong belief and trust on your translator. There is no other way that I can explain you.

At the first, this criteria must be noted in contract, but Trust and Conscience must be accompaigned.