I am not an attorney. But I have worked quite a bit in the area of contracts prior to retirement and I have dealt with a lot of construction contracts and gotten lots of help and advice from attorneys who are well qualified in the area of contract law. I have always been cautioned that there is such a thing as an oral contract. In other words, if two parties reach a meeting of the minds with respect to the provisions of an agreement, consideration is offered and accepted, and both parties begin performing according to the terms of the agreement that you may be legally deemed to have a valid and enforceable contract regardless of whether or not the agreement was formally signed. And I have seen this principle applied on more than one occasion. Would this not also apply to a NDA, which is actually a form of contract? If so, why the hoopla over whether or not Trump signed the NDA. It is obvious that an agreement was reached, consideration was paid, and both parties performed according to the agreement for a number of years. Would this not constitute a legally valid contract?