In a transfer, the problem of confidentiality of transmitted information to the potential buyer is very important.
Even if it is very difficult to prove the origin of the leaked confidential information, it is essential to have the potential buyer sign a non disclosure agreement, which will protect transmitted information before it is passed on.
Do not forget to mention in the agreement not to poach the personnel, as the potential buyer could have contact with certain key employees (people in sales and marketing, technicians, research and development).
The buyer must promise not to leak any confidential information and to only use this information for the evaluation of the current project.
They must also give back any information, whether written or electronic, if it is so demanded.
They must assure that these points are also respected by collaborators and advisors who are also working on the case.
Information already in the public domain or becoming public is not confidential unless one of the points above has been violated. It is the same case for information made public by the vendor.