Method and arrangement in a communication network

• US 20010016909A1
• Filed: 02/20/2001
• Published: 08/23/2001
• Est. Priority Date: 02/22/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Gehrmann, Christian
• Granted Patent: US 6,912,657 B2
• Time in Patent Office: Days
• US Class Current: 713/171
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

The present invention relates to the problem of establishing of security that arises within an ad hoc network

The problem is solved by using an optical device at a first device to read a public key that is encoded to a graphical string at a second device, which key is required for establishing security.

Claims

1. An ad hoc communications network (N) comprising

a first device (A) having an optical device (O) and a second device (B) having a pair of keys,

the key pair constituting a secret key and a public key,

the first device (A) having a user (U) that trusts the second device (B), characterised by

the public key being hashed to a bit string,

the bit string being encoded to a graphical string (S),

the graphical string being visible for the user (U) of the first device (A),

the first device (A) having means for obtaining the graphical string by means of the optical device (O),

the first device (A) having means for authenticating the second device (B) by means of the obtained string.

2. The ad hoc communications network according to

claim 1

, characterised in that the first device (A) after receiving a public key from the second device (B), trusts that key if it can be hashed to the string (S).

3. The ad hoc communications network according to

claim 1

, wherein the second device (B) constitutes a service device having a network address characterised by the graphical string being mapped to the network address.

4. The ad hoc communications network according to

claim 3

, characterised by the first device (A) having means for obtaining the network address, by means of the optical device (O).

5. The ad hoc communications network according to

claim 4

, characterised by the first device (A) having means for connecting to the service device by means of the obtained network address.

6. Method for establishing a security relation between a first device (A) and a second device (B) within an ad hoc communications network (N),

the first device (A) having an optical device (O),

the second device (13) having a pair of keys constituting a secret key and a public key,

the first device (A) having a user that trusts the second device (B), the method comprising the steps of:

hashing the public key to a bit string;

encoding the bit string to a graphical string (S);

making the graphical string (S) visible for the user of the first device (A),

the first device (A) obtaining the graphical string (S) by means of the optical device (O),

the first device (A) authenticating the second device (B) by means of the obtained graphical string (S).

7. The method according to

claim 6

, wherein the first device (A) after receiving a public key from the second device (B), trusting that key if it can be hashed to the string (S).

8. The method according to

claim 6

, wherein the second device (B) constitutes a service device having a network address comprising the further step of:

mapping the graphical string to the network address.

9. The method according to

claim 8

, comprising the further step to be taken by the first device (A):

obtaining the network address, by means of the optical device (O).

10. The method according to

claim 9

, comprising the further step to be taken by the first device (A):

connecting to the service device by means of the obtained network address.