Abstract: A system and method of conducting secure business-to-business transactions by exchanging commitments and secure transaction tokens, where two levels of verification stringency are used for increasing the efficiency while maintaining sufficient security. The commitments are verified by a more stringent standard, such as PKI operations while the secure transaction tokens are verified by a more efficient but less stringent standard such as hash operations. The transaction token both represents a monetary value and provides an instruction on how to treat the monetary value it represents. In other words, the token has dual attributes: value and type. Particular embodiments based on the well-known PayWord specification are disclosed.

Abstract: Embodiments include a method and a system of authenticating a client when the client logs in a servicing. According to one embodiment, a first authentication code and a second authentication code is submitted from the client to the servicing server. The second authentication code includes a secure token of a reversal secure token chain with a hash function and an index of the secure token in the reversal secure token chain. The first authentication code is then verified at the servicing server. The secure token is also verified at the servicing server by comparing a hash value of the secure token with a previously acquired secure token or a root of the reversal secure token chain. If the first authentication code and the second authentication code are associated, the login is confirmed.