Method for generating group key
A method is provided for generating a group key, including sharing a plurality of secret keys with a plurality of nodes adjacent to a first node of the plurality of nodes, obtaining a plurality of function values using the plurality of secret keys and a result value using the plurality of function values, broadcasting the result value, receiving a plurality of result values generated using a method by which the result value has been obtained, from nodes of the plurality of nodes except for a corresponding node, and obtaining a group key using a plurality of function values extracted from the plurality of function values and the plurality of result values.
1. A method of a node for generating a group key applied to a plurality of nodes, the method comprising:
sharing a first secret key with a first adjacent node of a plurality of adjacent nodes and sharing a second secret key with a second adjacent node of the plurality of adjacent nodes;
obtaining first and second function values by operating the first secret key and the second key;
obtaining a first result value using the first and second function values;
broadcasting the first result value to the plurality of other adjacent nodes;
receiving other result values from the plurality of other adjacent nodes; and
performing an operation on a plurality of function values extracted from the first function value and the other result values, to obtain a group key.
2. The method of claim 1 , wherein the operation comprises an XOR operation.
3. The method of claim 1 , wherein the obtaining of the inner result value comprises:
substituting the first and the second secret keys as values of a plurality of substitution values for a one-way function to obtain the first and second function values; and
performing an operation on the first and the second function values to obtain the result value.
4. The method of claim 3 , wherein the operation comprises an XOR operation.
5. The method of claim 3 , wherein the plurality of substitution values comprise a nonce value.
6. The method of claim 5 , further comprising generating the nonce value using time information.
7. The method of claim 1 , further comprising broadcasting the result value through an authentication channel.
8. The method of claim 1 , further comprising sharing the first and second secret keys using an out of band method.
9. The method of claim 1 , further comprising pre-setting the first and second secret keys.
10. The method of claim 9 , further comprising inputting the pre-set first and second secret keys.
11. A method of a node for generating a group key applied to a plurality of nodes, the method comprising:
sharing a plurality of secret keys with a plurality of other nodes adjacent to the node;
obtaining a plurality of function values by operating the plurality of secret keys;
obtaining a first result value using the plurality of function values;
broadcasting the first result value;
receiving a plurality of other result values generated based on the first result value, from the plurality of other nodes; and
obtaining a group key using the plurality of function values and the plurality of other result values.
12. A non transitory computer-readable medium including instructions for causing a processor to implement a method of a node for generating a group key applied to a plurality of nodes, the method comprising:
sharing a plurality of secret keys with a plurality of other nodes adjacent to the node;
obtaining a plurality of function values by operating the plurality of secret keys and for obtaining a first result value using the plurality of function values;
broadcasting the first result value;
receiving a plurality of other result values generated based on the first result value, from the plurality of other nodes; and
obtaining a group key using the plurality of function values and the plurality of other result values.
13. The method of claim 1 , wherein the first result value is obtained by operating the first function value and an inverse of the second function value.