A fairCASH deal has the following definition:
- Two prospective signatory entities mutually known sign a certain contract:
- Seller 'explains exchange' between 'goods or services' and 'payment' to buyer by invoice,
- Buyer 'explains exchange' by the payment transfer,
- Seller 'explains' the successful payment transfer to buyer by receipt,
- fCCP makes the transfer non-repudiational for both parties.
This is the pairing partnership association phase. Both entities enter into a P2P-based transaction relationship by mutually identify themselves:
- The initiator uses the application software to enter information about his action and creates the request.
- The initiator determines the method (there are different technical methods to do that, e.g. by using an NFC/RFID, a DNS/IP entry or a MSN) for contacting the other peer using a proximity or remote connection.
- The initiating eWallet contacts the target eWallet.
- Both eWallets exchange their certificates.
VPN/VPC setup phase
This is the setup phase for the VPN/VPC-session-initiation. A virtual private network or channel is being established:
- Both eWallets exchange key information.
- Both eWallets negotiate a VPN/VPC.
Both eWallets negotiate the intended deal. Part of this policy based checking process is the verification of enough value availability and other rules:
- Both eWallets exchange their user certificates.
- Both eWallets specify and acknowledge the deal.
- Both eWallets compare the other’s eWallet identity with the intended one.
- Both eWallets authorize or decline the deal.
Value data transfer
The payment is exchanged against an electronic receipt:
- The eCoins of the main payment are transferred.
- The eCoins of the change payment are transferred.
Both parties receive their irrefutable evidences to make the deal complete, repudiation-free and final (with the weak deal exception):
- The acknowledge tickets are sent.
- Both eWallets inform their respective users about the money transfer status.
- Both eWallets terminate the connection.
Execution transaction times for selected networks
A source of arrested attention for every payment system is the average transaction duration. Exemplary transaction time calculations for several network usage cases are listed in following table:
|Network Name||Uplink Speed||Round Trip Time||Processing Time||Run Time|
|RFID/NFC 106 kbit/s||64 kbit/s||20 ms||100 ms||5.7 s|
|RFID/NFC 212 kbit/s||127 kbit/s||20 ms||100 ms||3.4 s|
|RFID/NFC 424 kbit/s||256 kbit/s||20 ms||100 ms||2.3 s|
|RFID/NFC 848 kbit/s||352 kbit/s||20 ms||100 ms||1.9 s|
|RFID/NFC 6,78 Mbit/s||2.7 Mbit/s||20 ms||100 ms||1.2 s|
|RFID/NFC 13,56 Mbit/s||5.4 Mbit/s||20 ms||100 ms||1.2 s|
|GSM Standard CSD (Circuit Switched Data)||9.6 kbit/s||900 ms||100 ms||38.2 s|
|GPRS||25.6 kbit/s||1000 ms||100 ms||17.5 s|
|ISDN||62 kbit/s||200 ms||100 ms||6.7 s|
|UMTS Standard||51.2 kbit/s||400 ms||100 ms||8.7 s|
|EDGE (Enhanced Data Rates for GSM Evolution)||88 kbit/s||1865 ms||100 ms||13.7 s|
|T-DSL 2048/192||163 kbit/s||55 ms||100 ms||3.1 s|
|HSPA (High Speed Packet Access)||1.2 Mbit/s||260 ms||100 ms||2.5 s|
|HSUPA (High Speed Uplink Packet Access) Cat.2||1.2 Mbit/s||50 ms||100 ms||1.5 s|
|Bluetooth 2.0+EDR||2.0 Mbit/s||10 ms||100 ms||1.2 s|
|HSDPA (High Speed Downlink Packet Access)||5.8 Mbit/s||150 ms||100 ms||1.8 s|
|HSPA+||8.8 Mbit/s||100 ms||100 ms||1.5 s|
|WLAN IEEE 802.11g||20 Mbit/s||10 ms||100 ms||1.1 s|
|LTE (Long Term Evolution) or HSOPA (High Speed OFDM Packet Access) Basic||40 Mbit/s||25 ms||100 ms||1.1 s|
|Fast Ethernet||80 Mbit/s||1 ms||100 ms||1.0 s|
|WLAN IEEE 802.11n||100 Mbit/s||10 ms||100 ms||1.1 s|
|Giga Ethernet||800 Mbit/s||1 ms||100 ms||1.0 s|