Method to detect an OTA (over the air) standard message affected by an error
A method is to detect a message compatible with the OTA (Over The Air) standard and affected by a wrong ciphering. The method may include receiving the ciphered OTA message; deciphering the OTA message; and reading a counter field of padding bytes in the deciphered OTA message and reading corresponding padding bytes in the OTA message deciphered. The method may also include detecting at least one bit in at least one of the padding bytes of the OTA message deciphered, with the at least one bit being indicative of the wrong ciphering.
1. A method, comprising:
receiving a ciphered message compatible with an Over The Air (OTA) standard, the ciphered message being encrypted using a first cryptographic key of a cryptographic algorithm comprising a Data Encryption Standard algorithm, the ciphered message comprising padding bytes set to a first bit value;
deciphering the ciphered message using a second cryptographic key of the cryptographic algorithm to produce a deciphered OTA message, the second cryptographic key being different from the first cryptographic key;
determining a number of padding bytes of the deciphered OTA message; and
determining an incorrect ciphering in response to at least one bit of the padding bytes of the deciphered OTA message being set to a second bit value different from the first bit value or in response to the number of padding bytes of the deciphered OTA message not being in a predetermined interval, wherein the predetermined interval comprises integers greater than or equal to 0 and less than or equal to 7.
2. The method of claim 1 , wherein the deciphered OTA message comprises a counter field of padding bytes indicative of the number of padding bytes of the deciphered OTA message.
3. A method, comprising:
receiving a ciphered message, the ciphered message having been encrypted by a sender device using a first cryptographic key compatible with a cryptographic algorithm;
deciphering, using a second cryptographic key compatible with the cryptographic algorithm, the ciphered message, the deciphering producing a deciphered message comprising a data packet, padding bytes, and a counter field indicative of a number of the padding bytes of the deciphered message; and
determining that an incorrect ciphering has occurred in response to the counter field of the deciphered message having a value outside a numerical interval or in response to at least one bit of the padding bytes of the deciphered message being set to a first binary value, wherein the cryptographic algorithm comprises a Data Encryption Standard algorithm, and wherein the numerical interval comprises integers greater than or equal to 0 and less than or equal to 7.
4. The method of claim 3 , wherein each of the ciphered message and the deciphered message is compatible with an Over The Air (OTA) standard.
5. The method of claim 3 , wherein the ciphered message comprises padding bytes, each bit of the padding bytes of the ciphered message being set to a second binary value different from the first binary value.
6. The method of claim 5 , wherein the first binary value comprises binary value 1 and the second binary value comprises binary value 0.
7. The method of claim 3 , further comprising sending an error message indicative of a cryptographic error, the error message being devoid of information for generating the second cryptographic key.
8. The method of claim 3 , wherein the ciphered message is received by a secure electronic device.
9. The method of claim 8 , wherein the secure electronic device comprises an integrated circuit card.
10. The method of claim 3 , further comprising authenticating the sender device in response to a determination that the incorrect ciphering has occurred.
11. An electronic device, comprising:
a receiving circuit configured to receive a ciphered message, the ciphered message having been encrypted by a sender device using a first cryptographic key compatible with a cryptographic algorithm;
a deciphering circuit configured to decipher, using a second cryptographic key compatible with the cryptographic algorithm, the ciphered message, the deciphering producing a deciphered message comprising a data packet, padding bytes, and a counter field indicative of a number of the padding bytes of the deciphered message; and
a detection circuit configured to detect that an incorrect ciphering has occurred in response to the counter field of the deciphered message having a value outside a numerical interval or in response to at least one bit of the padding bytes of the deciphered message being set to a first binary value, wherein the cryptographic algorithm comprises a Data Encryption Standard algorithm, and wherein the numerical interval comprises integers greater than or equal to 0 and less than or equal to 7.
12. The electronic device of claim 11 , wherein the cryptographic algorithm is compatible with an Over The Air (OTA) standard.
13. The electronic device of claim 11 , wherein the electronic device comprises an integrated circuit card.
14. The electronic device of claim 11 , further comprising an authentication circuit configured to authenticate the sender device in response to a determination that the incorrect ciphering has occurred.
15. A method, comprising:
receiving a ciphered message compatible with an Over The Air (OTA) standard, the ciphered message being encrypted using a first cryptographic key of a cryptographic algorithm comprising an Advanced Encryption Standard algorithm, the ciphered message comprising padding bytes set to a first bit value;
deciphering the ciphered message using a second cryptographic key of the cryptographic algorithm to produce a deciphered OTA message, the second cryptographic key being different from the first cryptographic key;
determining a number of padding bytes of the deciphered OTA message; and
determining an incorrect ciphering in response to at least one bit of the padding bytes of the deciphered OTA message being set to a second bit value different from the first bit value or in response to the number of padding bytes of the deciphered OTA message not being in a predetermined interval, wherein the predetermined interval comprises integers greater than or equal to 0 and less than or equal to 15.
16. A method, comprising:
receiving a ciphered message, the ciphered message having been encrypted by a sender device using a first cryptographic key compatible with a cryptographic algorithm;
deciphering, using a second cryptographic key compatible with the cryptographic algorithm, the ciphered message, the deciphering producing a deciphered message comprising a data packet, padding bytes, and a counter field indicative of a number of the padding bytes of the deciphered message; and
determining that an incorrect ciphering has occurred in response to the counter field of the deciphered message having a value outside a numerical interval or in response to at least one bit of the padding bytes of the deciphered message being set to a first binary value, wherein the cryptographic algorithm comprises an Advanced Encryption Standard algorithm, and wherein the numerical interval comprises integers greater than or equal to 0 and less than or equal to 15.
17. The method of claim 16 , wherein each of the ciphered message and the deciphered message is compatible with an Over The Air (OTA) standard.
18. The method of claim 16 , wherein the ciphered message comprises padding bytes, each bit of the padding bytes of the ciphered message being set to a second binary value different from the first binary value.
19. The method of claim 18 , wherein the first binary value comprises binary value 1 and the second binary value comprises binary value 0.
20. The method of claim 16 , further comprising sending an error message indicative of a cryptographic error, the error message being devoid of information for generating the second cryptographic key.
21. The method of claim 16 , wherein the ciphered message is received by an integrated circuit card.