Method of operating a one-time pad system and a system for implementing this method

• US 20070074276A1
• Filed: 07/19/2006
• Published: 03/29/2007
• Est. Priority Date: 09/29/2005
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Sadler, Martin, Tofts, Christopher, Harrison, Keith, Spiller, Timothy, Munro, William
• Application Number:
  US11/490,478
• Publication Number:
  US 20070074276A1
• Time in Patent Office: Days
• US Class Current: 726/4
• CPC Class Codes: H04L 2209/127 Trusted platform modules [TPM]
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/0656 Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
• CPC Class Codes: H04L 9/0852 Quantum cryptography transmission systems employing electromagnetic waves other than radio waves, e.g. light, infrared H04B10/00; wavelength-division multiplex systems H04J14/02; WDM arrangements H04J14/03
• CPC Class Codes: H04L 9/3226 using a predetermined code, e.g. password, passphrase or PIN network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083

Abstract

A system is disclosed in which a plurality of devices are arranged to use one-time pad data to interact with apparatus holding the same one-time pad data. Each of the devices and the apparatus has its own one-time pad and the pads are all provisioned with the same new one-time pad data. Upon any one of the devices wishing to effect an interaction with the apparatus using one-time pad data, an alignment operation is carried out between a set of entities comprising at least the apparatus and the device wishing to carry out the interaction. The alignment operation serves to reduce the level of the one-time pad of at least the device wishing to carry out the interaction, to the level of the lowest one-time pad of the set of entities involved in the alignment operation.

Claims

1. A method of operating a system in which a plurality of devices are arranged to use one-time pad data to interact with apparatus holding the same one-time pad data, the method comprising:

provisioning respective one-time pads of the devices and apparatus with the same new one-time pad data;

upon any said device, herein the pending-active device, wishing to effect an interaction with the apparatus using one-time pad data, carrying out an alignment operation between a set of entities comprising at least the pending-active device and the apparatus, to reduce the level of at least the one-time pad of the pending-active device to the level of the lowest one-time pad of said set of entities.

2. A method according to claim 1, wherein the alignment operation reduces the levels of the one-time pads of all the entities of said set to the level of the lowest of these pads.

3. A method according to claim 1, wherein the set of entities comprises said plurality of devices and the apparatus.

4. A method according to claim 1, wherein the set of entities comprises the apparatus and those devices that are currently contactable to participate in the alignment operation.

5. A method according to claim 2, wherein the set of entities comprises the apparatus and multiple said devices, the alignment operation comprising:

the apparatus communicating with said multiple devices to ascertain the levels of the one-time pads of these devices;

the apparatus determining the level of the lowest one of the one-time pads of said set of entities;

the apparatus communicating to said multiple devices the level of the lowest one of the one-time pads of said set of entities; and

the apparatus and said multiple devices each reducing the level of its own one-time pad to the level of the lowest one of the one-time pads of said set of entities.

6. A method according to claim 1, wherein the constitution of said set of entities is dependent on a security level associated with the intended interaction with the apparatus, the set being required to include more said devices when the intended interaction has a higher security level.

7. A method according to claim 1, wherein the devices are also arranged to effect interactions with each other using their one-time pad data, each such interaction being preceded by the carrying out of an alignment operation between a further set of entities comprising at least the devices that are to participate in the interaction, to reduce the levels of the one-time pads of the entities of said further set to the level of the lowest one of these pads.

8. A method according to claim 7, wherein said further set of entities comprises said plurality of devices and the apparatus.

9. A method according to claim 1, wherein the provisioning of the one-time pads of the devices and apparatus with the same new one-time pad data is effected by:

provisioning a first said device and the apparatus with the same secret random data;

distributing said secret random data from the first device to one or more other said devices in a hierarchical distribution pattern headed by the first device; and

each device and the apparatus using the secret random data to provide said new one-time pad data for its one-time pad.

10. A method according to claim 1, wherein the provisioning of the one-time pads of the devices and apparatus with the same new one-time pad data is effected by:

provisioning each device and the apparatus with the same secret random data; and

each device and the apparatus using the secret random data as one-time pad data for its one-time pad.

11. A method according to claim 1, wherein the devices and apparatus have pre-existing one-time pads based on the same pre-existing one-time pad data, the provisioning of the one-time pads of the devices and apparatus with the same new one-time pad data is effected by:

(a) carrying out an alignment operation to reduce the levels of the one-time pads of the said plurality of devices and apparatus to the level of the lowest one of these pads;

(b) provisioning each device and the apparatus with the same secret random data; and

(c) the devices and apparatus each using the secret random data to provide said new one-time pad data by merging, according to a predetermined merge function, the secret random data with the existing one-time pad of that device or apparatus, the merge function being such that a party with knowledge of the secret random data, cannot derive any part of the merged data without also having knowledge of the existing one-time pad;

(a) and (b) being effected in any order unless (b) involves use of any said pre-existing one-time pad data in which case (a) is effected after (b).

12. A method according to claim 1, wherein the devices and apparatus have pre-existing one-time pads based on the same pre-existing one-time pad data, the provisioning of the one-time pads of the devices and apparatus with the same new one-time pad data being effected by:

(a) carrying out an alignment operation to reduce the level of the one-time pad of a first one of the devices to the level of the lowest one-time pad of said plurality of devices;

(b) carrying out an alignment operation to reduce the level of the one-time pads of the first device and apparatus to the level of the lowest one of these pads;

(c) provisioning the first device and the apparatus with the same secret random data;

(d) the first device and apparatus each using the secret random data to provide new one-time pad data by merging, according to a predetermined merge function, the secret random data with its existing one-time pad, the merge function being such that a party with knowledge of the secret random data, cannot derive any part of the merged data without also having knowledge of the existing one-time-pad; and

(e) the first device sharing its new one-time pad data with the other devices;

(b) and (c) being effected in any order unless (c) involves use of the existing one-time pads in which case (b) is effected after (c).

13. A system comprising:

apparatus with a one-time pad; and

a plurality of devices each with its own one-time pad that is the same as or a subset of the one-time pad held by the apparatus, each device being arranged to use one-time pad data from its one-time pad to interact with said apparatus;

wherein each device is so arranged that upon the device wishing to effect an interaction with the apparatus using one-time pad data, it participates in an alignment operation between a set of entities comprising at least itself and said apparatus, to reduce the level of at least its own one-time pad to the level of the lowest one-time pad of said set of entities.