eCash

ECash was the trademark name of an electronic payment system of the company DigiCash. It was especially suitable for payments in micropayment area. Used was a kind of voucher system in which each digital coin is anonymous represented by a digital serial number that has been saved on the hard disk of the user. In the late 1990s the system and the company behind it were shut down.

The e-cash inventor, David Chaum wanted to originally create an Internet system that allows political elections can be settled. For the output of the electronic " ballot " it was important that the issuer was authenticated, the user remained anonymous and used only a one-time use was possible. Since the idea of electronic voting at that time but have not yet met with resonance, Chaum looked for another possible application of his system. Since similar requirements also apply to cash, he used the principle for eCash.

Expiration

When e-cash method transfers a customer credit from his bank account to his e-cash account. This encrypted files are created with certain values ​​memories that are stored on his computer. The management of these electronic coins takes a special utility, the " electronic wallet " ( Cyberwallet or E- Wallet). When shopping on the Internet the seller are then transferred these files from the buyer's computer. When paying the digital cash is immediately checked for validity by the seller or the bank. The seller can now decide to send the ordered goods or the execution of the corresponding service.

Function

First, a customer has to open an e-cash account with a licensed bank for eCash and install an e-cash software on his computer. The e-cash account is linked to an actual bank account. The "loading" or " unloading " of an e-cash account can only be made from this bank account. If the customer wants to transfer an amount eCash that generates electronic wallet files in the amount of the desired amount. Each file is a certain value is assigned which is no longer changing. In addition it receives from the wallet a serial number. DigiCash refers to these files, therefore, as "electronic coins " ( Cybercoins ). The bank verifies the credit. Is it sufficient, each file is provided with a key of the bank, where each key corresponds to a specific value; the corresponding sum is debited from the "real" bank account. Subsequently, the files are sent to the customer, that is, returned to the purse. This process is similar to the charging of a chip card to a charging terminal. The files are now encoded by both the wallet with the client code as well as by the bank with which the key. The purse away now it has made in the key. This process is called DigiCash " Blinding ". By Blinding the absolute anonymity is preserved. Each file is thus made up of the serial number and the information about the value and is encrypted with the key of the bank. When outputting eCash the customer files whose value is the amount requested by the seller sends. Payment on the Internet with the help of e-cash software is possible in real time. On click, the software generates a demand for payment from the seller, which he sends to the wallet of the customer. This lets the customer confirm the transaction and sends files in the amount of the desired amount to the seller. This in turn forwards the electronic coins to the Bank. There, the bank key is removed, the value of the coin is credited to the e-cash account of the seller. The series has now been decrypted number is stored.

The naming of this invention gives the impression that it is cash - although be converted to eCash by the fixed connection of the system with a real bank account only so-called Giraleinlagen. Even so, the dealer requires for its posting for an e-cash account. This is significant in that it represents all critical areas such as money laundering, distribution of means of payment, etc. no problem. Actually eCash thus corresponds rather to a bank guarantee as a monetary system.

Pros and Cons

A dual use (double -spending ) of the files is impossible because once a serial number has been used, it can never be used again. A loss of monetary value can not be made unless the user has backed up his keys or the e -wallet and so the wallet can recover on the database server ( recovery mechanism ). During the time in which eCash was in use, no cases have been known abuse. The maximum credit amount on the e-wallet was, to around EUR 200 - limited.

The e-cash system has Though technically excellent way not very widespread, since the company DigiCash in a US- balancing method ( Chapter 11 ) skidded and the cryptologic patents have been taken over by a successor company. This has thrown regionally in the U.S. on voucher / online coupon system. The European e-cash license banks where the systems already operating well ran ( German Bank, Bank Austria and Credit Suisse) have after the end of the 1990s ended her e-cash support. The problem of converting between currencies was thus up to the last in the e-cash system never solved.

PayPal works today organizationally similar: from credit cards and bank accounts, the withdrawals are made and given to the dealer for the credit guarantee. A PayPal merchant account can back -transferred only to a real bank account - or in the system itself again be issued. The then very advanced features such as e-cash the delivery of digital coins via e -mail and the possibility of two individuals is to send itself amounts of money also covered by PayPal.