Computing Device with a Process-Based Keystore and method for Operating a Computing Device
A computing device is provided with a key manager which provides a mechanism for distinguishing between authorised use and unauthorized use of a cryptographic key by identifying an owning application for each key, which is authorised by the key manager to freely use a particular key, and is also trusted to ask for explicit confirmation from the user when considered appropriate, such as when the key is used in a signing operation. To allow for sharing of keys between applications, the owning application may be enabled to designate a list of other applications which are also trusted to use the key.
1 . A computing device arranged to provide secure use of data for cryptographic operations by
a. keeping each item of the said data in a keystore;
b. assigning ownership of items in the keystore to respective processes;
c. enabling respective processes to assign another process as a user of respective items;
d. enabling respective processes to delete or modify respective items; and
e. denying access to items in the keystore to processes that neither own an item nor have been assigned as a user of an item.
2 . A device according to claim 1 wherein access to items in the keystore is controlled by a single keystore process.
3 . A device according to claim 1 wherein the keystore process comprises a server.
4 . A device according to claim 3 wherein the keystore server is arranged to control access to cryptographic data kept in a further device.
5 . A device according to claim 1 wherein the items kept in the keystore include either cryptographic keys or security certificates, or both.
6 . A device according to claim 1 wherein access to items in the keystore is further restricted by a requirement for an authentication of identity from a user of the device.
7 . A device according to claim 6 wherein user authentication is by means of at least one of
a. manual entry of a passphrase or a PIN; or
b. verification of biometric data.
8 . A device according to claim 6 wherein user authentication is valid for a limited period of time.
9 . A device according to claim 8 where the period for which user identification is valid is varied between different processes.
10 . A device according to claim 1 comprising multiple keystores each of which may have access controlled either by separate keystore process or by a central keystore process.
11 . A device according to claim 1 in which the deletion or removal of a process from the device is accompanied by the deletion or removal of all items owned by the said process.
12 . A method of operating a computing device for providing secure use of data for cryptographic operations, the method comprising
a. keeping each item of the said data in a keystore;
b. assigning ownership of items in the keystore to respective processes;
c. enabling respective processes to assign another process as a user of respective items;
d. enabling respective processes to delete or modify respective items; and
e. denying access to items in the keystore to processes that neither own an item nor have been assigned as a user of an item.
13 . A method according to claim 12 wherein access to items in the keystore is controlled by a single keystore process.
14 . A method according to claim 12 wherein the keystore process comprises a server.
15 . A method according to claim 14 wherein the keystore server is arranged to control access to cryptographic data kept in a further device.
16 . A method according to claim 12 wherein the items kept in the keystore include either cryptographic keys or security certificates or both.
17 . A method according to claim 12 wherein access to items in the keystore is further restricted by a requirement for an authentication of identity from a user of the device.
18 . A method according to claim 17 wherein user authentication is by means of at least one of
a. manual entry of a passphrase or a PIN; or
b. verification of biometric data.
19 . A method according to claim 17 wherein user authentication is arranged to be valid for a limited period of time.
20 . A method according to claim 19 wherein the period for which user identification is valid is varied between different processes.
21 . A method according to claim 12 comprising using multiple keystores each of which has access controlled either by a separate keystore process or by a central keystore process.
22 . A method according to claim 12 in which the deletion or removal of a process from the device is accompanied by the deletion or removal of all items owned by the said process.
23 . An operating system for a computing device according to claim 1 .
24 . An operating system for causing a computing device to operate according to the steps of claim 12.