Untraceability is considered to be a sub property of privacy. It requires unlinkability and is a requirement for anonymity. It is effective if the evidence produced during an eCoin transaction is statistically independent of the information exchanged between the eMint and a user during the withdrawal and deposit phase. Please note, that this is general not achievable in the first and last eCoin operation during withdrawals and deposits, if the source or target for the balance is an identified account.
Digital Cash transactions should be fundamentally untraceable. It is a prerequisite for making any flow analysis of financial activities impossible. In our fairCASH system we have eCoins and eWallets as identifiable objects with serial numbers. However, these objects are not interrelated with each other or with a user identity. Therefore, there is no global hop-trace of moving eCoins visible for the eMint nor are the eCoins carrying any information about their owners or eWallet identities.
eCoin objects contain a serial number and can be identified. But due to the local nature of the hop-log the eMint or any other third party cannot mandate their usage. Nevertheless it is possible to offer the owners of these local stored transfer logs incentives to induce them for a release. This can be done by offering a reward for specific eCoins interested in or by doing a lottery for all posters. This could be one way of a bunch of other possibilities in the hypothetical case, if the tamper-resistance of an eWallet is broken and a party cannot be hindered from multi-spending. This offers a probabilistic chance of deriving the serial-number identity of the eWallet and user certificate.
All payment transfers within the fairCASH system are untraceable, honored as an indispensable value due to strict anonymity objectives.