Method and system for encryption and authentication
AssigneeImpsys AB
InventorMathias Widman
Life of this patent
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Abstract
A method and a system for encrypted transmission or authentication between at least two units via an insecure communication channel, comprising the steps of: (a) in an initiation procedure, producing a common original value to be used in the respective units; (b) synchronising a counting value in each unit; (c) generating a key on the basis of the original value and the counting value in each unit, independently of other units; and (d) using the thus generated key in a subsequent encrypted transmission or authentication operation.
Claims13
for encrypted transmission or authentication between at least two units via an insecure communication channel, comprising the steps of:
- in an initiation procedure, obtaining a common original value to be used in the respective units;
- synchronising a counting value in each unit;
- generating a key on the basis of the original value and the counting value in each unit, independently of other units;
- and
- using the thus generated keys in a subsequent encrypted transmission or authentication operation.
A method as claimed in any one of the preceding claims, wherein said key-generating operation on the basis of the original value and the counting value is effected by means of a calculating algorithm stored in a non-dynamic and non-changeable fashion in at least one of the units.
A method as claimed in any one of the preceding claims, wherein at least one of the units is a mobile unit, such as a smart card or a mobile telephone.
A method as claimed in any one of the preceding claims, wherein one of the units is a central unit comprising a plurality of original values for secure encrypted transmission or authentication with relation to several different units having one original value each.
A system for encrypted transmission/authentication between at least two units via an insecure communication channel, wherein each unit comprises a key-generating unit, said key-generating units comprising a memory, in which identical original values are stored, a counter to periodically change a counting value, and a calculating unit adapted to generate in each unit and independently of other units, a key on the basis of the original value and a counting value issued from the counter, said keys arranged to be used for encrypted transmission or authentication between the units.
Dependencies are inferred from the claim text.