| 摘要 |
<p>A method for detecting a speed violation of a vehicle traveling from a first roadside system ( G 1 ) to a second roadside system ( G 2 ) comprises:
setting-up private and public parameters ( g , p G ), including a common modulo basis ( p G ), of an identity based encryption (IBE) scheme in a key generation center ( KGC ) and the first and second roadside systems ( G 1 , G 2 );
capturing at least an identifier ( LPN ) of the vehicle and a first timestamp (t) at the first roadside system ( G 1 ) as first evidence data ( D ), using at least the first identifier ( LPN ) and first timestamp ( t ) as a first identity to generate a first IBE public key ( PK 1,t ), encrypting the first evidence data ( D ) with a first random session key ( K ), encrypting the first random session key ( K ) with the first IBE public key ( PK 1,t ), and deleting the first evidence data ( D ) and the first session key ( K ) at the first roadside system ( G 1 );
capturing at least an identifier ( LPN ) of the vehicle and a second timestamp ( t ) at the second roadside system ( G 2 ) as second evidence data ( D ), using at least the second identifier ( LPN ) and second timestamp ( t ) as a second identity to generate a second IBE public key ( PK 2,t ), encrypting the second evidence data ( D ) with a second random session key (K), encrypting the second random session key ( K ) with the second IBE public key ( PK 2,t ), and deleting the second evidence data ( D ) and the second session key ( K ) at the second roadside system ( G 2 );
calculating a ratio ( V ) of the first and second public keys ( PK 1,t , PK 2,t ), modulo the common modulo basis ( p G ), and looking-up the ratio ( V ) in a table of ratios ( V ) pre-computed for a set of time differences between said first and second timestamps ( t ) which set represents speed violations, and, when the look-up is successful:
retrieving at least one IBE private key ( SK 1 , SK 2 ) for at least one of said IBE public keys ( PK 1,t , PK 2,t ) from the key generation center ( KGC ), decrypting at least one of said encrypted session keys ( EK ) with said private key ( SK 1 , SK 2 ), and decrypting at least one of said encrypted evidence data ( ED ) with said decrypted session key ( K ).</p> |
