For electronic payments to be as effective and efficient as paper and coin currency, eCash should include the following properties:
One of the main properties surrounding eCash is security. When the determined amount is being transferred between consumers, merchants, and banks the prevention of any unauthorized individuals like hackers intercepting, or even changing, the content of the messages, such as the dollar amount, should be addressed. This is commonly addressed through encryption and special serial numbers that give the bank the power to verify the authenticity of the transaction.
Besides online security, physical security should be taken into account. For example, if a hard drive crashes or a smart card is stolen, the eCash could also be lost. Thanks to advances in technology, eCash can be stored on secure cloud databases so that it can be easily recovered.
Privacy, in regards to eCash, is the anonymity of the consumers who have made the payment. As with coins and paper notes, the payee should not be able to be linked or be traced during transactions. Privacy is important because consumers’ privacy should be protected from being monitored by financial surveillance. Anonymity, however, does present a number of concerns like counterfeiting, money laundering, and blackmailing in extreme circumstances. Keep in mind that the more anonymity that is offered the less security there will be.
One of the benefits of electronic cash is that it’s portable. It can be taken with you no matter where you are in the world. In fact, the portability of eCash could replace traditional wallets since it can be stored on your smartphone on in the cloud.
Another advantage of eCash is that it can be transferred from the payee to the payer without being referred to a bank. The ability to transfer between parties should be easy and convenient, just as with traditional paper and coins. Parties should also be able to exchange funds electronically to each other no matter where they are in the world.
When discussing divisibility, eCash denominations should be able to be divided into small amounts. This makes smaller transactions possible between parties. Arguably on the main challenges for divisible systems having the ability to divide the value into smaller amounts that will eventually be equal to the original value.
Previously, divisibility systems were solved by Eng, and Okamoto’s scheme, Okamoto’s scheme and Okamoto and Ohta’s scheme. More recently, International Association for Cryptologic Research shared a system by Patrick Märtens that is based on bounded accumulators and “a new technique to prove that several revealed values are inside an accumulator.”
As a whole, eCash payments do not just have to contain the features listed above. To truly replace traditional money transfers, electronic payments have to be more convenient, easier-to-use, and ubiquitous. That means that eCash networks must work with each other.