The first law is, "Don't reverse what you don't own".
When you pirate software, and then reverse it you do something that will bite you in the ass.
In the United States even if an artifact or process is protected by trade secrets, reverse-engineering the artifact or process is often lawful as long as it is obtained legitimately. Patents, on the other hand, need a public disclosure of an invention, and therefore, patented items do not necessarily have to be reverse-engineered to be studied. (However, an item produced under one or more patents could also include other technology that is not patented and not disclosed.) One common motivation of reverse engineering is to determine whether a competitor's product contains patent infringements or copyright infringements.
The reverse engineering of software in the US is generally a breach of contract as most EULAs specifically prohibit it, and courts have found such contractual prohibitions to override the copyright law which expressly permits it; see Bowers v. Baystate Technologies.
Sec. 103(f) of the DMCA (17 U.S.C. § 1201 (f)) says that if you legally obtain a program that is protected, you are allowed to reverse-engineer and circumvent the protection to achieve interoperability between computer programs (i.e., the ability to exchange and make use of information). The section states:
(f) Reverse Engineering.—
- Notwithstanding the provisions of subsection (a)(1)(A), a person who has lawfully obtained the right to use a copy of a computer program may circumvent a technological measure that effectively controls access to a particular portion of that program for the sole purpose of identifying and analyzing those elements of the program that are necessary to achieve interoperability of an independently created computer program with other programs, and that have not previously been readily available to the person engaging in the circumvention, to the extent any such acts of identification and analysis do not constitute infringement under this title.
- Not withstanding the provisions of subsections (a)(2) and (b), a person may develop and employ technological means to circumvent a technological measure, or to circumvent protection afforded by a technological measure, in order to enable the identification and analysis under paragraph (1), or for the purpose of enabling interoperability of an independently created computer program with other programs, if such means are necessary to achieve such interoperability, to the extent that doing so does not constitute infringement under this title.
The information acquired through the acts permitted under paragraph (1), and the means permitted under paragraph (2), may be made available to others if the person referred to in paragraph (1) or (2), as the case may be, provides such information or means solely for the purpose of enabling interoperability of an independently created computer program with other programs, and to the extent that doing so does not constitute infringement under this title or violate applicable law other than this section.
For purposes of this subsection, the term 「interoperability」 means the ability of computer programs to exchange information, and of such programs mutually to use the information which has been exchanged.
Article 6 of the 1991 EU Computer Programs Directive allows reverse engineering for the purposes of interoperability, but prohibits it for the purposes of creating a competing product, and also prohibits the public release of information obtained through reverse engineering of software.
In 2009, the EU Computer Program Directive was superseded and the directive now states:
(15) The unauthorised reproduction, translation, adaptation or transformation of the form of the code in which a copy of a computer program has been made available constitutes an infringement of the exclusive rights of the author. Nevertheless, circumstances may exist when such a reproduction of the code and translation of its form are indispensable to obtain the necessary information to achieve the interoperability of an independently created program with other programs. It has therefore to be considered that, in these limited circumstances only, performance of the acts of reproduction and translation by or on behalf of a person having a right to use a copy of the program is legitimate and compatible with fair practice and must therefore be deemed not to require the authorisation of the rightholder. An objective of this exception is to make it possible to connect all components of a computer system, including those of different manufacturers, so that they can work together. Such an exception to the author's exclusive rights may not be used in a way which prejudices the legitimate interests of the rightholder or which conflicts with a normal exploitation of the program.
Anyway, reversing a ticketing system will most probably be seen as illegal as there is nothing to gain expect from free travel exploitation. If you represent a university you might get this done legally.