Secure vehicle access method and system

1. A vehicle access method

for a vehicle which can be driven by different users, including a primary user and a secondary user, which is equipped with a keyless entry system, and which stores a master key, a primary key, a secondary key, and a tertiary key, and

a remote data server, which stores server data including identification information of the primary user, an elliptic encryption curve, the master key, the primary key, the secondary key and the tertiary, and

a first personal device which belongs to the primary user, which includes an application that is configured to connect to the keyless entry system and to the server, and which stores the identification information of the primary user and the elliptic encryption curve,

the access method comprises a data exchange phase including the following successive steps:

b1) sending the identification information of the primary user to the server via the application installed on the first personal device;

b2) receiving at the first personal device from the server encrypted server data using the elliptic encryption curve for the encryption, the encrypted server data including the secondary key, the tertiary key, and an encrypted master key using the primary key for the encryption,

the first personal device being configured to use the elliptic encryption curve to decrypt the encrypted server data, such that the first personal device stores the secondary key, the tertiary key, and the encrypted master key;

the access method subsequently comprises an access phase including the following successive steps:

c1)establishing at the vehicle a secure connection of the first personal device with the vehicle, implementing the tertiary key provided by the first personal device;

c2) if the secure connection procedure is successful, sending the encrypted master key to the vehicle from the first personal device

wherein the vehicle is configured to decrypt the encrypted master key using the primary key, and

after decryption, the vehicle is configured to control the keyless entry system such that the primary user can access the vehicle using the application installed on the first personal device.

2. The vehicle access method of claim 1 , which also comprises:

b3) receiving via the application installed on the first personal device identification information of a secondary user;

b4) generating via the application installed on the first personal device access data, including the encrypted master key;

b5) generating via the application installed on the first personal device encrypted access data, using the secondary key for the encryption;

b6) generating via the application installed on the first personal device encrypted mobile data using the elliptic encryption curve for the encryption, the encrypted mobile data including the tertiary key, and the encrypted access data;

b7)transmitting from the application installed on the first personal device the encrypted mobile data to the application installed on the second personal device which is configured to use

the elliptic encryption curve to decrypt the encrypted mobile data, such that the second personal device stores the tertiary key, and the encrypted access data and to establish

a secure connection with the vehicle, implementing the tertiary key and to transmit the encrypted access data to the vehicle which is configured to use

the secondary key to decrypt the encrypted access data and

after decryption, the vehicle is configured to recognize the access data and controls the keyless entry system, such that the secondary user can access the vehicle using the application installed on the second personal device.

3. Access method according to claim 2 , wherein step b4) occurs after the primary user uses the application installed on the first personal device to agree to lend the vehicle to the secondary user.

4. Access method according to claim 2 , prior to step b4), the primary user defines conditions for accessing the vehicle and in that in step b4) the access data include, on the one hand, the encrypted master key using the primary key for the encryption and on the other hand, the predefined access conditions.

5. Access method according to claim 2 , characterized in that in step b3), the identification information of the secondary user include an email address, a name and/or a telephone number.

6. Access method according to claim 2 , characterized in that the application installed on the second personal device is configured to connect to the server, under certain conditions.

7. Access method according to claim 2 , characterized in that the second personal device is a mobile telephone.

8. Access method according to claim 2 , characterized in that the second personal device is an electronic watch, a digital tablet, or a passive entry card.

9. Access method according to claim 1 , characterized in that the first personal device is a mobile telephone.

10. Access method according to claim 1 , characterized in that the first personal device is an electronic watch, a digital tablet, or a passive entry card.

11. Access method according to claim 1 , characterized in that in step b1), the identification information of the primary user include an email address, a name and/or a telephone number.

12. Access method according to claim 1 , characterized in that the master key defined for the vehicle is attributed to the primary user and is modified when the vehicle is associated with a new primary user.

13. Access method according to claim 1 , characterized in that the elliptic encryption curve is a Diffie-Hellman elliptic curve.

14. A vehicle access method for a vehicle which can be driven by different users, including a primary user and a secondary user, which is equipped with a keyless entry system, and which stores a master key, a primary key, a secondary key, and a tertiary key, and a remote data server, which stores server data including identification information of the primary user, an elliptic encryption curve, the master key, the primary key, the secondary key and the tertiary key, and a first personal device which belongs to the primary user, which includes an application that is configured to connect to the keyless entry system and to the server, and which stores the identification information of the primary user and the elliptic encryption curve, the access method comprises a data exchange phase including the following successive steps:

b1) sending the identification information of the primary user to the server via the application installed on the first personal device;

b2) receiving at the server the identification information of the primary user sent from the application installed on the first personal device;

b3) generating via the server encrypted server data using the elliptic encryption curve for the encryption, the encrypted server data including the secondary key, the tertiary key, and an encrypted master key using the primary key for the encryption;

b4) sending the encrypted server data to the first personal device which is configured to use the elliptic encryption curve to decrypt the encrypted server data, such that the first personal device stores the secondary key, the tertiary key, and the encrypted master key;

the access method subsequently comprises an access phase including the following successive steps:

c1) establishing a secure connection via the first personal device with the vehicle, implementing the tertiary key;

c2) sending to the vehicle from the first personal device the encrypted master key to the vehicle wherein the vehicle is configured to decrypt the encrypted master key using the primary key and after decryption, control the keyless entry system such that the primary user can access the vehicle using the application installed on the first personal device.

15. The method of claim 14 , which also comprises:

b5) receiving via the application installed on the first personal device identification information of a secondary user;

b6) generating via the application installed on the first personal device access data, including the encrypted master key;

b7) generating via the application installed on the first personal device encrypted access data, using the secondary key for the encryption;

b8) generating via the application installed on the first personal device encrypted mobile data using the elliptic encryption curve for the encryption, the encrypted mobile data including the tertiary key, and the encrypted access data;

b9) transmitting from the application installed on the first personal device the encrypted mobile data to an application installed on the second personal device which is configured to use the elliptic encryption curve to decrypt the encrypted mobile data, such that the second personal device stores the tertiary key, and the encrypted access data and to establish a secure connection with the vehicle, implementing the tertiary key and to transmit the encrypted access data to the vehicle which is configured to use the secondary key to decrypt the encrypted access data and after decryption, the vehicle is configured to recognize the access data and controls the keyless entry system, such that the secondary user can access the vehicle using the application installed on the second personal device.

16. A vehicle access method for a vehicle which can be driven by different users, including a primary user and a secondary user, which is equipped with a keyless entry system, and which stores a master key, a primary key, a secondary key, and a tertiary key, and a remote data server, which stores server data including identification information of the primary user, an elliptic encryption curve, the master key, the primary key, the secondary key and the tertiary key, and a first personal device which belongs to the primary user, which includes an application that is configured to connect to the keyless entry system and to the server, and which stores the identification information of the primary user and the elliptic encryption curve, the access method comprises a data exchange phase including the following successive steps:

b1) sending the identification information of the primary user to the server via the application installed on the first personal device;

b2) receiving at the first personal device encrypted server data from the server, where the encrypted server data includes the secondary key, the tertiary key, and an encrypted master key using the primary key for the encryption;

b3) decrypting the encrypted server data via the first personal device using the elliptic encryption curve, such that the first personal device stores the secondary key, the tertiary key, and the encrypted master key;

the access method subsequently comprises an access phase including the following successive steps:

c1) establishing a secure connection via the first personal device with the vehicle, implementing the tertiary key;

c2) sending to the vehicle from the first personal device the encrypted master key to the vehicle;

c3) decrypting the encrypted master key at or by the vehicle using the primary key; and

c4) controlling the keyless entry system such that the primary user can access the vehicle using the application installed on the first personal device.

17. The method of claim 16 , which also comprises:

b4) receiving via the application installed on the first personal device identification information of a secondary user;

b5) generating via the application installed on the first personal device access data, including the encrypted master key;

b6) generating via the application installed on the first personal device encrypted access data, using the secondary key for the encryption;

b7) generating via the application installed on the first personal device encrypted mobile data using the elliptic encryption curve for the encryption, the encrypted mobile data including the tertiary key, and the encrypted access data;

b8) transmitting from the application installed on the first personal device the encrypted mobile data to an application installed on the second personal device which is configured to use the elliptic encryption curve to decrypt the encrypted mobile data, such that the second personal device stores the tertiary key, and the encrypted access data and to establish a secure connection with the vehicle, implementing the tertiary key and to transmit the encrypted access data to the vehicle which is configured to use the secondary key to decrypt the encrypted access data and after decryption, the vehicle is configured to recognize the access data and controls the keyless entry system, such that the secondary user can access the vehicle using the application installed on the second personal device.