Trust is defined as "the assured reliance on the character, ability, strength, or truth of someone or something, or one in which confidence is placed."
When conducting a transaction in the 'real' world as opposed to the virtual world, there is a level of trust at work gained through experience. Any system using currency has deep-seated trust. When someone purchases any merchandise and pays for it by cash, the merchant trusts that these bills are legal tender, not counterfeit, and will be accepted when he tenders them for deposit or purchase. For some, the currency of the United States is considered the safest in the world because a majority trusts that the United States government will always fully back it.