Trade Secret is defined in Israel as business information of any kind, which is not in the public domain, and cannot easily be retrieved by others.
An owner of a trade secret may keep an advantage over his commericial rivals as long as his secret is not exposed. This can last for many years, and possibly for good (a common example of trade secrets is Coca-Cola's secret formula, allegedly kept as a secret for over a century!).
The moment the secret is exposed the owner loses his advantage and usually cannot prevent others from using the information previously kept as a trade secret (but for very limited reasons, such as in the case of a secret exposed in a wrongdoing). That moment can occur after long years of secrecy or after a vary short time, depending on the nature of the secret and how well it is kept.
In the patent realm, a fundamental principle is the disclosure of the invention subject to the patent. This means that the know-how that might have been kept as a secret, is no longer a secret. But the owner of the patent can exercise his rights in preventing others from using his patented invention for as long as his patent is valid (in most countries patent protection lasts from the issue date - and sometimes even earleir - until 20 years lapse from the filing date of the patent application).
As reverse engineering and technical analysis techniques become more and more developed and efficient keeping a trade secret confidential becomes substantially more difficult and intricate, making more people turn to patenting their inventions rather than keeping them as secrets.
