Working Definitions

TRUST

Is a relationship of reliance. A trusted party seeks to fulfill policies, ethical codes, law and their previous promises. Trust does not need to involve belief in the good character or morals of the other party. Persons engaged in a criminal activity usually trust each other to some extent. Trust is a prediction of reliance on an action, based on what a party knows about the other party. Trust is a statement about what is otherwise unknown -- for example, because it is far away, cannot be verified, or is in the future.
The degree to which one party trusts another is a measure of belief in the honesty and competence of the other party. Based on the most recent research, a failure in trust may be forgiven more easily if it is interpreted as a failure of competence rather than a lack of honesty.  Trustworthiness is a moral value considered to be a virtue. A trustworthy person is someone in whom we can place our trust and not be betrayed. A person can prove his trustworthiness by fulfilling an assigned responsibility - and to not let down our expectations. In order for one to trust another, their worth and integrity must be constantly proven over time.
[Origin: 1175–1225; (n.) Middle English < Old Norse traust trust]

LAW

 A rule of conduct established and enforced by the authority, legislation, or custom of a given community, state, or nation. 
[Origin: before 1000; Middle English law(e), lagh(e), Old English lagu < Old Norse [Iceland] *lagu, early pl. of lag layer, stratum, a laying in order, fixed tune, (in collective sense) law; akin to lay, lie]

ETHICS

Ethics is a major branch of philosophy that involves analysis of right conduct. It is a process of rational thinking in order to survive. The purpose of ethics, according to Aristotle, is happiness.  Ethics also involves a life worth living or life that is satisfying. 
[Origin: 1400–50; late ME ethic + -s³, via Latin ethica from the Ancient Greek ἠθική [φιλοσοφία] "moral philosophy", from the adjective of ἤθος ēthos "custom, habit"]

ETHICS LAWS

While ethics is about should, laws are about must. Laws prohibit or mandate specific conduct. Obeying the law is a matter of compliance, and illegal conduct results in sanctions including fines and imprisonment.

Ethics laws meld the two concepts. They both require conduct such as open meetings and disclosure of financial interests and forbid transactions that could compromise the integrity of government. Because of a high tendency of those regulated to evade the spirit and purpose of such laws, statutes have become more complex and technical.

Michael Josephson

CORRUPTION

Corruption is an abuse of public power for private gain that goes against the public interest. … corruption entails a confusion of the private with the public sphere or an illicit exchange between the two spheres. In essence, corrupt practices involve public officials acting in the best interest of private concerns (their own or those of others) regardless of, or against, the public interest.  (United Nations definition) 
[Origin: 1300–50; Middle English corrupcio(u)n (< AF) < Latin corruptiōn-, s. of corruptiō. See corrupt] CORRUPT:[Origin: 1250–1300; Middle English < Latin corruptus broken in pieces, corrupted, equiv. to cor- + rup- (var. s. of rumpere to break) + -tus]