| 5878140 |
Limited-traceability systems |
| Mar-2-1999 |
Cryptographic methods and apparatus for payment and related transaction systems are disclosed that allow some kinds of tracing under some conditions and make substantially infeasible other kinds of tracing... |
| 5878138 |
System and method for detecting fraudulent expenditure of electronic assets |
| Mar-2-1999 |
An electronic asset system includes tamper-resistant electronic wallets that store non-transferable electronic assets. To break such tamper-resistant wallets, the criminal is expected to spend an initial... |
| 5872844 |
System and method for detecting fraudulent expenditure of transferable electronic assets |
| Feb-16-1999 |
An electronic asset system includes tamper-resistant electronic wallets that store transferable electronic assets. To break such tamper-resistant wallets, the criminal is expected to spend an initial investment... |
| 5862224 |
Cryptographic process for protection against fraud |
| Jan-19-1999 |
A cryptographic process is for protection against fraud. An allocation of a secret key K is made to a card and to an application and an input value R is defined. The card and application calculate the... |
| 5832089 |
Off-line compatible electronic cash method and system |
| Nov-3-1998 |
An off-line electronic cash system having an electronic coin, a bank B, a payee S, and a user U with an account at the bank B as well as a user password z.sub.u,i, has a method for performing an electronic... |
| 5799087 |
Electronic-monetary system |
| Aug-25-1998 |
An electronic-monetary system having (1) banks or financial institutions that are coupled to a money generator device for generating and issuing to subscribing customers electronic money including electronic... |
| 5781631 |
Limited-traceability systems |
| Jul-14-1998 |
Cryptographic methods and apparatus for payment and related transaction systems are disclosed that allow some kinds of tracing under some conditions and make substantially infeasible other kinds of tracing... |
| 5774553 |
Foreign exchange transaction system |
| Jun-30-1998 |
A realtime multilateral foreign exchange settlement system having a computer implemented netting system, a processor-based multilateral settlement coordinator (MSC) having a first money module and a first... |
| 5768385 |
Untraceable electronic cash |
| Jun-16-1998 |
An electronic cash protocol including the steps of using a one-way function f.sub.1 (x) to generate an image f.sub.1 (x.sub.1) from a preimage x.sub.1 ; sending the image f.sub.1 (x.sub.1) in an unblinded... |
| 5712913 |
Limited-traceability systems |
| Jan-27-1998 |
Cryptographic methods and apparatus for payment and related transaction systems are disclosed that allow some kinds of tracing under some conditions and make substantially infeasible other kinds of tracing... |
| 5557518 |
Trusted agents for open electronic commerce |
| Sep-17-1996 |
A system for open electronic commerce having a customer trusted agent securely communicating with a first money module, and a merchant trusted agent securely communicating with a second money module. Both... |
| 5521980 |
Privacy-protected transfer of electronic information |
| May-28-1996 |
Cryptographic apparatus and means are disclosed for each of three types of participants in an electronic system for privacy-protected transfer of certified information. This invention reveals protocols... |
| 5511121 |
Efficient electronic money |
| Apr-23-1996 |
A unique electronic cash system protects the privacy of users in legitimate transactions while at the same time enabling the detection of a double spender of the same electronic coin. The electronic cash... |
| 5455407 |
Electronic-monetary system |
| Oct-3-1995 |
An improved monetary system using electronic media to exchange economic value securely and reliably. The invention provides a complete monetary system having electronic money that is interchangeable with... |
| 5453601 |
Electronic-monetary system |
| Sep-26-1995 |
An improved monetary system using electronic media to exchange economic value securely and reliably. The invention provides a complete monetary system having electronic money that is interchangeable with... |
| 5436971 |
Method of and circuit arrangement for checking a smart card |
| Jul-25-1995 |
Prepaid smart cards which serve to procure services, for example from a public telephone, comprise a memory for value units which are debited in conformity with the service procured, i.e. are marked as... |
| 5305383 |
Method of electronic payment by chip card by means of numbered tokens allowing the detection of fraud |
| Apr-19-1994 |
Method of electronic payment by chip card. According to the invention, each token carries a number making it possible to check its authenticity. The invention is used for electronic payment. |
| 5276736 |
Optionally moderated transaction systems |
| Jan-4-1994 |
A tamper-resistant part is disclosed that can conduct transactions with an external system through a moderating user-controlled computer or that can on other occasions be brought into direct connection... |
| 5245657 |
Verification method and apparatus |
| Sep-14-1993 |
A prover possessing public information and related secret information sends the public information and an initial message to a verifier. The verifier sends back a random message and an enquiry generated... |
| 5224162 |
Electronic cash system |
| Jun-29-1993 |
In an electronic cash system, K sets of blind signature information are derived from secret information containing identification information of a user, K/2 sets of them are opened and a bank attaches... |
| 5131039 |
Optionally moderated transaction systems |
| Jul-14-1992 |
A tamper-resistant part is disclosed that can conduct transactions with an external system through a moderating user-controlled computer or that can on other occasions be brought into direct connection... |
| 4996711 |
Selected-exponent signature systems |
| Feb-26-1991 |
Digital signature techniques are disclosed in which exponents may be selected by the message to be signed itself, by the signing party, by the party providing the message to the signing party for signature,... |
| 4987593 |
One-show blind signature systems |
| Jan-22-1991 |
Numbers standing for cash money can be spent only one time each, otherwise the account from which they were withdrawn would be revealed. More generally, a technique for issuing and showing blind digital... |
| 4977595 |
Method and apparatus for implementing electronic cash |
| Dec-11-1990 |
In an electronic cash implementing method, a user makes a bank apply a blind signature to user information Vi produced, by a one-way function, from secret information Si containing identification information,... |
| 4969189 |
Authentication system and apparatus therefor |
| Nov-6-1990 |
In the case where a prover A proves the validity of a pretender B to a verifier C, B receives an initial response x' created by A, randomizes it with a random component and sends it as x", and randomizes... |
| 4947430 |
Undeniable signature systems |
| Aug-7-1990 |
Cryptographic methods and apparatus for forming, checking, blinding, and unblinding of undeniable signatures are disclosed. The validity of such signatures is based on public keys and they are formed by... |
| 4926480 |
Card-computer moderated systems |
| May-15-1990 |
A user controlled card computer C and communicating tamper-resistant part T are disclosed that conduct secure transactions with an external system S. All communication between T and S is moderated by C,... |
| 4914698 |
One-show blind signature systems |
| Apr-3-1990 |
Numbers standing for cash money can be spent only one time each, otherwise the account from which they were withdrawn would be revealed. More generally, a technique for issuing and showing blind digital... |
| 4204113 |
System for keeping account of predetermined homogenous units |
| May-20-1980 |
A system for keeping account of predetermined homogeneous units by means of an article such as a card, carrying information which may be the amount of a credit balance, and an external device for operating... |
