Systems and methods for preventing transmitted cryptographic parameters from compromising privacy
View Patent ↗A method for secure cryptographic communication includes transmitting information that identifies a group key from a first device to a second device. The method further includes, in the first device, using the group key to encrypt an input vector, transmitting the encrypted input vector, encrypting privacy-sensitive information using a device key, an encryption algorithm, and the input vector, and transmitting the encrypted privacy-sensitive information to the second device.
1. A method of updating a group encryption key associated with a radio frequency identification (RFID) tag, the method comprising:
receiving, at the RFID tag, an encrypted group encryption key from an RFID device, wherein the group encryption key has been encrypted using a tag encryption key of the RFID tag;
decrypting, at the RFID tag, the encrypted group encryption key using the tag encryption key;
encrypting, at the RFID tag, an initialization vector using the group encryption key;
transmitting the encrypted initialization vector from the RFID tag to the RFID device;
encrypting, at the RFID tag, privacy-sensitive data using the tag encryption key and the initialization vector; and
transmitting the encrypted privacy-sensitive data from the RFID tag to the RFID device.
2. The method as recited in claim 1 , wherein the group encryption key is used by the RFID tag and another RFID device different from the RFID device.
3. The method as recited in claim 1 , wherein the tag encryption key is unique to the RFID tag.
4. The method as recited in claim 1 , further comprising transmitting plaintext data referencing the group encryption key from the RFID tag to the RFID device.
5. The method as recited in claim 4 , wherein the plaintext data referencing the group encryption key comprises privacy-insensitive information.
6. The method as recited in claim 5 , wherein the privacy-insensitive information comprises information associated with at least one of the following: an issuing authority and an expiration date.
7. A radio frequency identification (RFID) tag, comprising:
an antenna;
a memory configured to store a group encryption key, a tag encryption key, an initialization vector, and privacy-sensitive information; and
a processor coupled with the memory and the antenna, the processor configured to:
receive an encrypted group encryption key from an RFID device, wherein the encrypted group encryption key has been encrypted using the tag encryption key;
decrypt the encrypted group encryption key using the tag encryption key
encrypt the initialization vector using the group encryption key;
transmit the encrypted initialization vector to the RFID device;
encrypt privacy-sensitive data using the tag encryption key and the initialization vector; and
transmit the encrypted privacy-sensitive data to the RFID device.
8. The RFID tag as recited in claim 7 , wherein the group encryption key is used by the RFID tag and another RFID device different from the RFID device.
9. The RFID tag as recited in claim 7 , wherein the tag encryption key is unique to the RFID tag.
10. The RFID tag as recited in claim 7 , wherein the processor is further configured to transmit plaintext data referencing the group encryption key to the RFID device.
11. The RFID tag as recited in claim 10 , wherein the plaintext data referencing the group encryption key comprises privacy-insensitive information.
12. The RFID tag as recited in claim 11 , wherein the privacy-insensitive information comprises information associated with at least one of the following: an issuing authority and an expiration date.
13. A communication system, comprising:
a radio frequency identification (RFID) tag; and
an RFID device;
the RFID tag comprising:
an antenna;
a memory configured to store a group encryption key, a tag encryption key, an initialization vector, and privacy-sensitive data; and
a processor coupled with the memory and the antenna, the processor configured to:
receive an encrypted group encryption key from the RFID device, wherein the encrypted group encryption key has been encrypted using the tag encryption key;
decrypt the encrypted group encryption key using the tag encryption key;
encrypt the initialization vector using the group encryption key;
transmit the encrypted initialization vector to the RFID device;
encrypt the privacy-sensitive data using the tag encryption key and the initialization vector; and
transmit the encrypted privacy-sensitive data to the RFID device.
14. The communication system as recited in claim 13 , wherein the group encryption key is used by the RFID tag and another RFID device different from the RFID device.
15. The communication system as recited in claim 13 , wherein the tag encryption key is unique to the RFID tag.
16. The communication device as recited in claim 13 , wherein the processor is further configured to transmit plaintext data referencing the group encryption key to the RFID device.
17. The communication system as recited in claim 16 , wherein the plaintext data referencing the group encryption key comprises privacy-insensitive information.
18. The communication system as recited in claim 16 , wherein the RFID device comprises:
an antenna; and
a processor coupled with the antenna, the processor configured to
receive, from the RFID tag, the plaintext data referencing the group encryption key;
use the plaintext data to identify the group encryption key;
receive the encrypted initialization vector from the RFID tag;
receive the encrypted privacy-sensitive data from the RFID tag;
decrypt the encrypted initialization vector using the group encryption key; and
decrypt the encrypted privacy-sensitive data using the decrypted initialization vector.
19. The communication system as recited in claim 18 , wherein the plaintext data referencing the group encryption key comprises privacy-insensitive information and the privacy-insensitive information comprises information associated with at least one of the following: an issuing authority and an expiration date.