Method for Generating a Secret or a Key in a Network

Patent metadata

Field	Value
Publication number	US-2018123786-A1
Application number	US-201615575839-A
Country	US
Kind code	A1
Filing date	Apr 13, 2016
Priority date	May 22, 2015
Publication date	May 3, 2018
Grant date	—

Abstract

Disclosed is a method for generating a secret or key in a network having first and second subscribers and a transmission channel therebetween. The first and second subscribers generating first and second sequences of subscriber values to achieve synchronous transmission; and the first and second subscriber each generate a common secret, the first subscriber doing so based on information about the first sequence and a superposition of the second sequence onto the first sequence on the transmission channel, and the second subscriber doing so based on information about the second sequence and the superposition of the second sequence of subscriber values onto the first sequence of subscriber values. At certain intervals or in accordance with a detected sequence of superposed values, the first or second subscriber outputs at least one filler value onto the transmission channel such that an edge change or change in values occurs on the transmission channel.

First claim

1 . A method for generating one of a secret and a key in a network, the network having at least a first user and a second user with a common transmission channel between at least the first user and the second user, the first user being configured to provide at least a first value and a second value to the transmission channel, the second user being configured to provide at least the first value and the second value to the transmission channel, the method comprising:
synchronously transmitting, on the transmission channel, a first user value sequence with the first user and a second user value sequence with the second user; generating one of a common secret and a common key, with the first user, based on information about the first user value sequence and based on a superimposition value sequence resulting from a superimposition of the first user value sequence with the second user value sequence on the transmission channel; generating one of a common secret and a common key, with the second user, based on information about the second user value sequence and based on the superimposition value sequence resulting from the superimposition of the first user value sequence with the second user value sequence on the transmission channel; providing at least one stuffing value to the transmission channel, one of (i) at particular intervals and (ii) depending on a detected superimposition value sequence, one of (i) with the first user outside of the first user value sequence and (ii) with the second user outside of the second user value sequence, such that one of a change of edges and a change of values takes place on the transmission channel.

2 . The method as claimed in claim 1 , wherein only one of the first user and the second user applies the at least one stuffing value to the transmission channel, the method further comprising:
detecting the at least one stuffing value with the other one of the first user and the second user.

3 . The method as claimed in claim 2 , the method further comprising:
determining, with the other one of the first user and the second user, synchronisation information using the detected stuffing value.

4 . The method as claimed in claim 1 , the providing of the at least one stuffing value further comprising:
providing, with the first user, at least one first stuffing value outside the first user value sequence and, with the second user synchronous therewith, at least one second stuffing value outside the second user value sequence to the transmission channel such that the one of the change of edges and the change of values takes place on the transmission channel due to a superimposition of the at least one first stuffing value and the at least one second stuffing value.

5 . The method as claimed in claim 1 , further comprising:
applying, with one of the first user the second user, the stuffing value to the transmission channel in response to a superimposition value sequence having a predetermined number of identical values being detected by one of the first user the second user.

6 . The method as claimed in claim 5 , the providing of the at least one stuffing value further comprising:
applying the at least one stuffing value directly as next value to the transmission channel as soon as the superimposition value sequence having the predetermined number of identical values is detected.

7 . The method as claimed in claim 5 , the providing of the at least one stuffing value further comprising:
applying the at least one stuffing value with a delay by a certain number of values to the transmission channel ( 30 ) after the superimposition value sequence having the predetermined number of identical values is detected.

8 . The method as claimed in claim 5 , wherein the stuffing value is inverse to the detected identical values.

9 . The method as claimed in claim 7 , the providing of the at least one stuffing value further comprising:
applying the stuffing value in fixed predetermined intervals, after a predetermined number of values of the first and second user value sequences applied to the channel, to the transmission channel.

10 . The method as claimed in claim 1 , the providing of the at least one stuffing value further comprising:
applying at least two stuffing values are applied to the transmission channel.

11 . The method as claimed in claim 10 , wherein the two stuffing values contain a change of values.

12 . The method as claimed in claim 1 , wherein, on the transmission channel;
a state corresponding to the first value occurs when both the first user and the second user initiate a transmission of the first value over the transmission channel; and a state corresponding to the second value occurs when at least one of the first user and the second user initiate a transmission of the second value over the transmission channel.

13 . The method as claimed in claim 1 , the synchronously transmitting further comprising:
generating the first user value sequence in the first user locally using one of a random number generator and pseudo-random number generator; and generating the second user value sequence in the second user locally using one of a random number generator and pseudo-random number generator.

14 . The method as claimed in claim 1 , wherein the at least one first stuffing value and the at least one second stuffing value are not utilized for generating the common secret or the common key.

15 . A method for generating one of a secret and a key with a first user of a network, the first user being is configured to receive information via a transmission channel from a second user of the network and to transmit information to the second user, the first user being configured to provide at least a first value and a second value to the transmission channel and to be able to detect the first value and the second value, the method comprising:
transmitting, with the first user, a first user value sequence synchronously to a transmission of a second user value sequence by the second user on the transmission channel; generating one of a common secret and a common key, with the first user based on information about the first user value sequence and based on the basis of a superimposition value sequence which results on the transmission channel from the superimposition of the first user value sequence with the second user value sequence; and providing, one of at particular intervals and depending on a detected superimposition value sequence, with the first user, at least a first stuffing value outside the first user value sequence to the transmission channel, such that one of a change of edges and a change of values takes place on the transmission channel.

16 . The method as claimed in claim 15 , wherein the network is one of a CAN, TTCAN, CAN-FD, LIN and I2C bus system, in which the first value is a recessive bus level and the second value is a dominant bus level.

17 . The method as claimed in claim 1 , further comprising:
providing, in the network, an on-off-keying amplitude shift keying configured to transmit data.

18 . A network comprising:
a first user, the first user being configured to provide at least a first value and a second value to the transmission channel; a second user, the second user being configured to provide at least the first value and the second value to the transmission channel; and a transmission channel, via which the first user communicates with the second user, wherein the first user is configured to transmit a first user value sequence on the transmission channel and the s

Assignees

• Bosch Gmbh Robert

Inventors

• Lothspeich Timo
• Mueller Andreas

Classifications

• H04L9/0861

  Generation of secret information including derivation or calculation of cryptographic keys or passwords · CPC title

• H04L2209/84

  Vehicles · CPC title

• H04L9/0838 Primary

  Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these (network architectures or network communication protocols for key exchange in a packet data network H04L63/061) · CPC title

• H04L9/12

  Transmitting and receiving encryption devices synchronised or initially set up in a particular manner · CPC title