Electronic transaction risk management

1. A method of detecting unauthorized activity in an electronic message transfer system comprising a plurality of storage and transfer devices associated with respective users of the electronic message transfer system, each storage and transfer device being configured to generate and receive cryptographically secured transfer messages for exchanging content with other storage and transfer devices in the system, the method comprising:

each storage and transfer device:

accumulating audit information in a memory of the storage and transfer device, the accumulated audit information comprising audit information relating to a plurality of transfer messages generated or received by the storage and transfer device; and

embedding encrypted audit information in each transfer message generated by the storage and transfer device, the embedded encrypted audit information comprising encrypted audit information relating to at least two transfer messages generated or received by the storage and transfer device, the encrypted audit information being encrypted using a first key that is different from a second key used to cryptographically secure the transfer message; and

at least one of the plurality of storage and transfer devices receiving cryptographically secured transfer messages and forwarding copies of the received cryptographically secured transfer messages to a secure server configured to decrypt and analyse the audit information embedded in each received cryptographically secured transfer message to detect unauthorized activity;

wherein each storage and transfer device comprises an Application Specific Integrated Circuit (ASIC) configured to implement the memory and a processor of the storage and transfer device.

2. The method of claim 1 , further comprising:

at least one storage and transfer device detecting a predetermined condition; and

in response to the detected condition, the at least one storage and transfer device notifying a user of the storage and transfer device to contact a service provider to reset the storage and transfer device, wherein during a subsequent reset operation, at least part of the accumulated audit information is forwarded to the secure server.

3. The method of claim 2 , wherein the predetermined condition is selected from the list of: an accumulated number of transactions; an accumulated value of funds exchanged with other devices; a limit value of funds transferred in any single transaction; a limit value of funds stored in the device.

4. The method of claim 1 , wherein the first key is unknown to a user of the storage and transfer device.

5. The method of claim 1 , wherein encrypted audit information is embedded in the transfer message before the transfer message is cryptographically secured using the second key, such that subsequent alteration of the audit information embedded within the cryptographically secured transfer message can be detected.

6. An electronic message transfer system comprising:

a plurality of storage and transfer devices associated with respective users of the electronic message transfer system, each storage and transfer device being configured to generate and receive cryptographically secured transfer messages for exchanging content with other storage and transfer devices in the system, each storage and transfer device comprising an Application Specific Integrated Circuit (ASIC) implementing:

a memory configured to accumulate audit information relating to a plurality of transfer messages generated or received by the storage and transfer device; and

a processor configured to embed encrypted audit information in each transfer message generated by the storage and transfer device, the embedded encrypted audit information comprising encrypted audit information relating to at least two transfer messages generated or received by the storage and transfer device the encrypted audit information being encrypted using a first key that is different from a second key used to cryptographically secure the transfer message; and

at least one of the plurality of storage and transfer devices being configured to receive cryptographically secured transfer messages and forwarding copies of the received cryptographically secured transfer messages to a secure server configured to decrypt and analyse the audit information embedded in each received cryptographically secured transfer message to detect unauthorized activity.

7. The system of claim 6 , wherein at least one storage and transfer device is configured to:

detect a predetermined condition; and

in response to the detected condition, notify a user of the storage and transfer device to contact a service provider to reset the storage and transfer device, wherein during a subsequent reset operation, at least part of the accumulated audit information is forwarded to the secure server.

8. The system of claim 7 , wherein the predetermined condition is selected from the list of: an accumulated number of transactions; an accumulated value of funds exchanged with other devices; a limit value of funds transferred in any single transaction; a limit value of funds stored in the storage and transfer device.

9. The system of claim 6 , wherein the first key is unknown to the user of the storage and transfer device.

10. The system of claim 6 , wherein encrypted audit information is embedded in the transfer message before the transfer message is cryptographically secured using the second key, such that subsequent alteration of the audit information embedded within the cryptographically secured transfer message can be detected.