Method of verifying the validity of an electronic parking ticket

1. A method of verifying the validity of an electronic parking ticket issued by a ticket machine, said ticket including parking data stored in memory of an electronic entity placed in a vehicle, the method comprising:

wirelessly and securely obtaining said electronic ticket from said electronic entity;

making available at least some of the parking data;

wirelessly and securely obtaining from said electronic entity a digital certificate of the electronic entity and a cryptographic signature of said electronic ticket,

wherein said digital certificate is based on specific data specific to said vehicle and a public key of said electronic entity, and only said electronic entity has a private key associated with said digital certificate, and

wherein said cryptographic signature is calculated by said ticket machine while incorporating therein said electronic ticket and said digital certificate;

making available at least a portion of said specific data; and

verifying said digital certificate to authenticate said electronic entity.

2. The verification method according to claim 1 , further comprising comparing said at least a portion of the specific data with a characteristic of said vehicle.

3. The verification method according to claim 2 , wherein said characteristic comprises a visible mark that can be seen on the outside of said vehicle.

4. The verification method according to claim 3 , wherein said characteristic comprises a number etched on an element of said vehicle.

5. The verification method according to claim 1 , wherein making available said at least a portion of said specific data comprises displaying said specific data on a screen of said inspection device.

6. The verification method according to claim 1 , wherein said cryptographic signature S is cryptographically calculated by one of the following formulas:

S=Sig KBpriv ( H ( T ,CERT KTpub )); or

S=Sig KBpriv ( H ( T,ID )), in which:

Sig KBpriv is a signature function with the private key KP priv of said ticket machine; and

H is a hashing function.

7. An electronic entity for being placed in a vehicle, said entity comprising:

first memory to store specific data that is specific to said vehicle;

second memory to store an electronic parking ticket issued by a ticket machine, the ticket including parking data for said vehicle and a cryptographic signature of said electronic ticket, said cryptographic signature being calculated by the ticket machine while incorporating therein said electronic ticket and a digital certificate associating a public key of said electronic entity with said specific data, wherein only said electronic entity has a private key associated with said digital certificate; and

wireless communication means for securely transmitting said electronic ticket, said specific data and said signature to an inspection device.

8. The electronic entity according to claim 7 , wherein the electronic entity comprises a transponder.

9. An inspection device for verifying the validity of an electronic parking ticket issued by a ticket machine stored in a memory of an electronic entity placed in a vehicle, the inspection device comprising:

wireless communication means for securely obtaining from said electronic entity said ticket, data specific to said vehicle and a cryptographic signature of said electronic parking ticket, said cryptographic signature being calculated by said ticket machine while incorporating therein said electronic ticket and a digital certificate associating a public key of said electronic entity with said specific data, wherein only said electronic entity has a private key associated with said digital certificate; and

means for making available at least some of the parking data included in said ticket and at least a portion of said specific data.

10. The inspection device according to claim 9 , wherein said wireless communication means comply with the NFC standard.

11. The inspection device according to claim 9 , wherein said wireless communication means comprise very short range communication means having a range of less than 60 cm.

12. The inspection device according to claim 11 , wherein said wireless communication means has a range of less than 30 cm.

13. The inspection device according to claim 12 , wherein said wireless communication means has a range of from about 10 cm to about 15 cm.

14. The inspection device according to claim 9 , wherein said means for making available comprises a display screen.

15. The inspection device according to claim 9 , further comprising memory to store the public key.