Stateless access stratum security for cellular internet of things
Aspects of security schemes (e.g., integrity protection, encryption, or both) are described. A measure of access stratum security can be realized without overhead associated with establishing and/or maintaining the per-cellular-device access stratum security context at a Cellular Internet of Things (CIoT) base station (C-BS). A gateway (e.g., a CIoT Serving Gateway Node (C-SGN)) may derive a first key. The first key may be only known to the C-SGN. The C-SGN may derive a second key from the first key and a parameter unique to the C-BS. The C-SGN may also derive a third key from the second key and an identity of a cellular device. The C-SGN may send the second and third keys to the C-BS and cellular device, respectively. Small data messages encrypted and/or integrity protected by the cellular device may be decrypted and/or verified by the C-BS.
1. An apparatus, comprising:
a communication interface to communicate with a node of a communication network;
a processing circuit coupled to the communication interface, the processing circuit adapted to:
obtain a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtain a small data message including a device identity and a first integrity protection value;
obtain a third key that is based on the second key and the device identity;
obtain a second integrity protection value that is based on the third key;
compare the first integrity protection value to the second integrity protection value;
discard the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
send the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the first integrity protection value and the second integrity protection value are obtained using at least one nonce and/or a time stamp, and the processing circuit is further adapted to:
provision a first nonce and/or the time stamp to a device identified by the device identity; and/or
obtain a second nonce from the device.
2. The apparatus of claim 1 , wherein the processing circuit is further adapted to: provision the first nonce and/or the time stamp and obtain the second nonce during a random access procedure.
3. The apparatus of claim 1 , wherein the small data message is encrypted with the third key, and the processing circuit is further adapted to:
decrypt the small data message using the third key.
4. The apparatus of claim 1 , wherein the processing circuit is further adapted to:
monitor a traffic load value;
detect that the traffic load value exceeds a predetermined threshold value; and
send a message, to a device that is identified by the device identity, that requests the device to include the first integrity protection value in a next one or more messages sent to the apparatus, in response to detecting that the traffic load value exceeds the predetermined threshold value.
5. The apparatus of claim 4 , wherein a network configures the predetermined threshold value.
6. The apparatus of claim 1 , wherein the processing circuit is further adapted to:
obtain the second key from the gateway.
7. The apparatus of claim 6 , wherein the gateway is Cellular Internet of Things serving gateway node (C-SGN).
8. The apparatus of claim 1 , wherein the apparatus is a Cellular Internet of Things (CIoT) base station (C-BS) or an Evolved Node B (eNodeB), and wherein the parameter unique to apparatus is a C-BS Identity or an eNodeB Identity.
9. The apparatus of claim 1 , wherein the processing circuit is further adapted to:
obtain the first integrity protection value and the second integrity protection value using at least one nonce and/or a time stamp.
10. The apparatus of claim 1 , wherein the processing circuit is further adapted to:
negotiate an access stratum security configuration during an initial attach procedure with a device, wherein the access stratum security configuration specifies whether small data messages are sent from the device without security, with integrity protection, with encryption, with integrity protection and encryption, and/or with on-demand integrity protection, wherein integrity protection and encryption are performed using the third key.
11. An apparatus, comprising:
a communication interface to communicate with a node of a communication network;
a processing circuit coupled to the communication interface, the processing circuit adapted to:
obtain a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtain a small data message including a device identity and a first integrity protection value;
obtain a third key that is based on the second key and the device identity;
obtain a second integrity protection value that is based on the third key;
compare the first integrity protection value to the second integrity protection value;
discard the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value; and
send the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the processing circuit is further adapted to:
monitor a traffic load value;
detect that the traffic load value exceeds a predetermined threshold value; and
send a message, to a device that is identified by the device identity, that requests the device to include the first integrity protection value in a next one or more messages sent to the apparatus, in response to detecting that the traffic load value exceeds the predetermined threshold value.
12. The apparatus of claim 11 , wherein the first integrity protection value and the second integrity protection value are obtained using at least one nonce and/or a time stamp, and the processing circuit is further adapted to:
provision a first nonce and/or the time stamp to a device identified by the device identity; and/or
obtain a second nonce from the device.
13. The apparatus of claim 12 , wherein the processing circuit is further adapted to:
provision the first nonce and/or the time stamp and obtain the second nonce during a random access procedure.
14. The apparatus of claim 11 , wherein the small data message is encrypted with the third key, and the processing circuit is further adapted to:
decrypt the small data message using the third key.
15. The apparatus of claim 11 , wherein a network configures the predetermined threshold value.
16. The apparatus of claim 11 , wherein the processing circuit is further adapted to:
obtain the second key from the gateway.
17. The apparatus of claim 16 , wherein the gateway is Cellular Internet of Things serving gateway node (C-SGN).
18. The apparatus of claim 11 , wherein the apparatus is a Cellular Internet of Things (CIoT) base station (C-BS) or an Evolved Node B (eNodeB), and wherein the parameter unique to apparatus is a C-BS Identity or an eNodeB Identity.
19. The apparatus of claim 11 , wherein the processing circuit is further adapted to:
obtain the first integrity protection value and the second integrity protection value using at least one nonce and/or a time stamp.
20. The apparatus of claim 11 , wherein the processing circuit is further adapted to:
negotiate an access stratum security configuration during an initial attach procedure with a device, wherein the access stratum security configuration specifies whether small data messages are sent from the device without security, with integrity protection, with encryption, with integrity protection and encryption, and/or with on-demand integrity protection, wherein integrity protection and encryption are performed using the third key.
21. A method of communication of an apparatus, comprising:
obtaining a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtaining a small data message including a device identity and a first integrity protection value;
obtaining a third key that is based on the second key and the device identity;
obtaining a second integrity protection value that is based on the third key;
comparing the first integrity protection value to the second integrity protection value;
discarding the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
sending the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the first integrity protection value and the second integrity protection value are obtained using at least one nonce and/or a time stamp, and the method further comprises:
provisioning a first nonce and/or the time stamp to a device identified by the device identity; and/or
obtaining a second nonce from the device.
22. An apparatus, comprising:
means for obtaining a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
means for obtaining a small data message including a device identity and a first integrity protection value;
means for obtaining a third key that is based on the second key and the device identity;
means for obtaining a second integrity protection value that is based on the third key;
means for comparing the first integrity protection value to the second integrity protection value;
means for discarding the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
means for sending the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the first integrity protection value and the second integrity protection value are obtained using at least one nonce and/or a time stamp, and the apparatus further comprises:
means for provisioning a first nonce and/or the time stamp to a device identified by the device identity; and/or
means for obtaining a second nonce from the device.
23. A non-transitory processor-readable medium storing processor-executable code, comprising code for causing a processor of an apparatus to:
obtain a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtain a small data message including a device identity and a first integrity protection value;
obtain a third key that is based on the second key and the device identity;
obtain a second integrity protection value that is based on the third key;
compare the first integrity protection value to the second integrity protection value;
discard the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
send the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the first integrity protection value and the second integrity protection value are obtained using at least one nonce and/or a time stamp, and further comprising code for causing the processor of the apparatus to:
provision a first nonce and/or the time stamp to a device identified by the device identity; and/or
obtain a second nonce from the device.
24. A method of communication of an apparatus, comprising:
obtaining a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtaining a small data message including a device identity and a first integrity protection value;
obtaining a third key that is based on the second key and the device identity;
obtaining a second integrity protection value that is based on the third key;
comparing the first integrity protection value to the second integrity protection value;
discarding the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
sending the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the method further comprises:
monitoring a traffic load value;
detecting that the traffic load value exceeds a predetermined threshold value; and
sending a message, to a device that is identified by the device identity, that requests the device to include the first integrity protection value in a next one or more messages sent to the apparatus, in response to detecting that the traffic load value exceeds the predetermined threshold value.
25. An apparatus, comprising:
means for obtaining a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
means for obtaining a small data message including a device identity and a first integrity protection value;
means for obtaining a third key that is based on the second key and the device identity;
means for obtaining a second integrity protection value that is based on the third key;
means for comparing the first integrity protection value to the second integrity protection value;
means for discarding the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
means for sending the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the apparatus further comprises:
means for monitoring a traffic load value;
means for detecting that the traffic load value exceeds a predetermined threshold value; and
means for sending a message, to a device that is identified by the device identity, that requests the device to include the first integrity protection value in a next one or more messages sent to the apparatus, in response to detecting that the traffic load value exceeds the predetermined threshold value.
26. A non-transitory processor-readable medium storing processor-executable code, comprising code for causing a processor of an apparatus to:
obtain a second key that is based on a first key and a parameter unique to the apparatus, wherein the first key is unknown to the apparatus and known to a gateway;
obtain a small data message including a device identity and a first integrity protection value;
obtain a third key that is based on the second key and the device identity;
obtain a second integrity protection value that is based on the third key;
compare the first integrity protection value to the second integrity protection value;
discard the small data message if a comparison result indicates that the first integrity protection value is not equal to the second integrity protection value;
send the small data message to the gateway if the comparison result indicates that the first integrity protection value is equal to the second integrity protection value; and
wherein the non-transitory processor-readable medium storing processor-executable code, further comprises code for causing the processor of the apparatus to:
monitor a traffic load value;
detect that the traffic load value exceeds a predetermined threshold value; and
send a message, to a device that is identified by the device identity, that requests the device to include the first integrity protection value in a next one or more messages sent to the apparatus, in response to detecting that the traffic load value exceeds the predetermined threshold value.