18 U.S.C. Sec. 152(1) defines concealment as the intentional act of concealing or withholding property from the knowledge of another person who has a legal right to that property or to knowledge of the act. Under this statute, concealment can take two forms: active concealment and passive concealment. Active concealment involves actively hiding or disguising the property, such as through fraud or false statements. Passive concealment involves the failure to reveal or disclose the property, such as through omissions or silence. Both active and passive concealment can be criminal offenses if done with the intent to defraud another person or entity.