1. Lightweight security protocols for the IoT
Shahid Raza
PhD, Senior Researcher
SICS Swedish ICT, Kista

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3. Internet of Things (IoT)
Network of globally identifiable physical objects/things
Mostly resource-constrained, lossy wireless networks
Multi-hop
Unattended deployments
Extremely heterogeneous
IPv6, an IoT enabling technology and integration layer
IPv6 over Low power Wireless Personal Area Network (6LoWPAN)
IPv6
Com. IPv6
6LoWPAN
Border Route (6BR)
6LoWPAN
Internet

4. IoT Security Internet Communication Security Network Security
Confidentiality
Integrity
Authentication
Network Security
Availability
Data-at-rest Security
Confidentiality
Integrity
Software Security
IPv6
com. IPv6
6BR
Internet
6LoWPAN

5. Communication Security in the IoT Solution developed in FP7 CALIPSO are being used in H2020 NobelGrid

6. Communication Security in the IoT
Per hop security
End-to-End (E2E) security
com-IPv6
IPv6
Internet
6BR
Internet protocol based
Lightweight but compliant with existing standards.

7. IoT and Security Protocols
CoAP, CoAPs
DTLS
comp. DTLS
UDP
comp. UDP
IPv6
com. IPv6
IPsec
com. IPsec
Ethernet/WiFi
security
HTTP
CoAP
TLS
DTLS
IPv6
com. IPv6
IPsec
Ethernet
UDP
Comp. UDP
CoAP, CoAPs
UDP
DTLS IP
RPL
IKE/IPsec
6LoWPAN
IEEE
HTTP/HTTPs, CoAP/CoAPs
TCP, UDP
TLS, DTLS IP
IKE/IPsec
Ethernet
6BR
Conventional Internet
6LoWPAN
Standard compliance is the key.
E2E security is the key

8. Secure CoAP (CoAPs) CoAP enables secure web in the IoT
HTTP + TLS = HTTPS
Reliable and synchronous transport (TCP)
CoAP + DTLS = CoAPs
Unreliable and asynchronous transport (UDP)
coaps://mySite:port/myResource
Actual overhead comes from DTLS

9. The DTLS Handshake 9

10. Extending 6LoWPAN-compression to DTLS
ClientHello is the first message sent to establish a secure session and for negotiation of crypto algorithms.
The current 6LoWPAN specification define compression schemes for UDP/IP protocol.
IP Datagram with ClientHello
Compressed
ClientHello

11. Lightweight DTLS Header size comparison DTLS Header
Without Compression [bit]
With Compression [bit]
%Saving
Record
104 40
62%
Handshake 96 24
75%
ClientHello
336
264
23%
ServerHello
304
14%

12. Lightweight DTLS Example: IP datagram with ClientHello Protocol
Uncompressed [bytes]
Compressed [bytes] IP 40 7
UDP 8 4
DTLS Record 13
DTLS Handshake 12
ClientHello (Minimal) 42 17
Total
115 35
Shahid Raza, et al., Lithe: Lightweight Secure CoAP for the Internet of Things.
IEEE Sensors Journal, 13(10), , October 2013.

13. IP security (IPsec) End-to-End security at the network layer
Authentication Header (AH)
Integrity and authentication
Encapsulated Security Payload (ESP)
Confidentiality and optionally integrity and authentication
Transport and Tunnel modes
Manually shared keys or use Internet Key Exchange (IKE)
Recommended for IPv6
Compare it with DTLS

14. IEEE 802.15.4 Security Per-hop security at the link layer
The application controls the security required
By default – “NO Security”
Four types of packets
Beacon, Data, ACK, Control packets for MAC Layer
NO Security for ACK packets
Shahid Raza, et al., Secure Communication for the Internet of Things - A Comparison of Link-Layer Security and IPsec for 6LoWPAN. Journal of Security and Communication Networks, 7(12), 2014

15. Security vs. Flexibility
Per hop
At lower layers
Header protection too
Protocol agnostic
End-to-End (E2E)
At upper layers
Protocols bound

16. Lets use them SICSthSense Contiki OS
Open source open license operating system for IoT
implementations of most IoT protocols
IPv6
6LoWPAN
CoAP, RPL
IEEE
IPsec
IKEv2
DTLS, etc.
OAuth 2.0 (Coming…)
SICSthSense
An open source and open license cloud platform for IoT

17. Performance Evaluation

18. DTLS Handshake – Different Security Modes

19. DTLS Handshake – Individual Messages

20. IPsec vs. IEEE 802.15.4 security Multi hops with 512 byte data size
Average Response Time [ms]
No. of hops

21. Key Management in IoT
Security Modes
Pre-shared key (PSK) – State-of-the-art in sensor network
Raw-public key (RPK)
Certificate-based - State-of-the-art in Internet

22. DTLS with Scalable Symmetric Keys
An IoT node needs to recognize and remember only one device, the Trust Anchor (TA)
DTLS Standard compliant
Standard compliance is the key.
Kc becomes a pre-shared key.
Also for RPK
Shahid Raza, et al., S3K: Scalable Security with Symmetric Keys - DTLS Key Establishment for the Internet of Things. IEEE Transactions on Automation Science and Engineering, 2016

23. Digital Certificates in the IoT
Certificate based cyber security protocols
Datagram TLS (DTLS)
IKEv2/IPsec
Object security
IoT Standards specifying digital certificates
CoAP
LwM2M
IPSO Objects
ETSI
Enrollment
Process of certifying digital keys/certificates

24. A Current Research Project
The CEBOT project: It aims to equip IoT devices with capabilities that will enable them to obtain digital certificate(s) in a secure and automated way and by using the communication protocols that these devices speak.
Partners
SICS Swedish ICT, Stockholm
Technology Nexus (neXus)
Endorsers

25. Conclusions IoT is nothing but an Internet
6LoWPAN is the main enabler for IoT
6LoWPAN is a generic way to connect constrained networks with the Internet and it can be applied to security protocols
Communication security in the IoT can be achieved using standardized Internet security protocols.
Both IPsec and DTLS are feasible to use in the IoT
Lightweight IKEv2/IPsec and DTLS have similar overhead
Compressed IPsec is more efficient than IEEE security for multi-hop network with bigger data sizes

26. Thank you! Questions?
Source code and publications:
Part of the work is carried out within the SIA Internet of Things, a joint effort by VINNOVA, Formas and the Swedish Energy Agency