State of the Art of Secure Internet of Things (S-IoT):The Development of New Cryptographic Key Updating Schemes
to Improve the Security ofLong-Range Wide Area Network (LoRaWAN) Protocol
Kalamullah Ramli and Nur Hayati
Co-Founder, Indonesia Cyber Awareness and Resilience (id-CARE) Institute
Professor, Electrical Engineering Department

Universitas Indonesia
International Conference on ASEAN JAPAN Cybersecurity Community 2023

OUTLINE• Introduction: IoT Use Case and IoT Security Threats• LoRaWAN Security• LoRaWan Security Issues• Proposed Solutions:• Root Key Update Scheme• Session Key Update Scheme• Conclusions

International Conference on ASEAN JAPAN Cybersecurity Community

IoT Networks

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IoT Security Threats• An IoT attack is a malicious attempt to exploit vulnerabilities in Internetconnected devices such as smart office devices, industrial control system,
and critical infrastructure key components• Attackers may seize control of the device, steal sensitive data, or use thedevice as a part of a botnet for other malicious purposes• With limited resources and processing power, IoT devices may lacksecurity features to protect against attacks, making them more vulnerableto attacks than other IT equipment

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IoT Security Threat(in numbers)
The number of Internet of Things (IoT)
cyber attacks worldwide amounted toover 112 million in 2022. Over therecent years, this figure has increased
significantly from around 32 million
detected cases in 2018. In the latest
measured year, the year-over-yearincrease in the number of Internet ofThings (IoT) malware incidents was 87
percent

Source: Statista, Feb 2023
https://www.statista.com/statistics/1377569/w
orldwide-annual-internet-of-things-attacks/

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Why LoRaWAN ?
• LoRaWAN become the standard of Internet of Things(IoT) Low Power Wide Area Network (LPWAN) through
ITU-TY.4480 recommendation (Des, 2021)

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https://www.itu.int/rec/T-REC-Y.4480/en•

https://lora-alliance.org/lora-alliance-press-release/lorawanformally-recognized-as-itu-international-standard-for-low-powerwide-area-networking/•https://blog.semtech.com/lorawan-formally-recognized-as-an-ituinternational-standard

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Why LoRaWAN ?
• The Number of IoT Connections in 2023 is 1,716.99 Million.
LoRa connections reach ± 42.55% of the total or as many as730.69 million (Source: Statista, July 2023)• There are 5.9 million LoRa gateways, 300 million end
devices/nodes, and 181 public network operators. LoRa
technology has been applied to various sectors (Source:Semtech, August 2023)

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https://www.statista.com/statistics/880822/lpwan-ic-market-share-by-technology/
https://www.semtech.com/lora7

LoRaWAN Security
1. Mutual authentication
2. Data Integrity
3. Data Confidentiality

AES
128 bit

LoRaWAN security mechanisms rely on
the AES cryptographic algorithms

MIC: Message Integrity Code• Mutual authentication is established between a LoRaWAN end-device and the LoRaWAN network
as part of the network join procedure through Over-the-Air-Activation (OTAA). The OTAA Join
Procedure proves that both the end device and the network have the knowledge of the root key,specifically AppKey.
• Data Integrity and Confidentiality Protection: All LoRaWAN traffic is protected using the twosession keys. Each payload is encrypted by AES-CTR and carries a frame counter (to avoid packetreplay) and a Message Integrity Code (MIC) computed with AES-CMAC (to avoid packet tampering).
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Gemalto, Actility, and Semtech, “"LoRaWANTM Security A White Paper.” Accessed: Dec. 03, 2021. [Online]. Available:
https://lora-alliance.org /sites/lorawan_security_whitepaper.pdf

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LoRaWAN Security• LoRaWAN security uses the AES
cryptographic algorithm for integrity
protection and encryption.
• Each LoRaWAN device ispersonalized with a unique 128 bit
AES key (called root key)o Root key LoRaWAN consist ofNwkKey & AppKey• LoRaWAN session keys are then derived, one for providing integrity protection and encryption of theLoRaWAN MAC commands and application payload (the NwkSKey), and one for end-to-end encryption ofapplication payload (the AppSKey).
o The NwkSKey is distributed to the LoRaWAN network in order to prove/verify the packets authenticity & integrity.
o The AppSKey is distributed to the application server in order to encrypt/decrypt the application payload.
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N. Hayati, K. Ramli, S. Windarta and M. Suryanegara, "A Novel Secure Root Key Updating Scheme for LoRaWANs Based on
CTR_AES DRBG 128," in IEEE Access, vol. 10, pp. 18807-18819, 2022, doi: 10.1109/ACCESS.2022.3150281.

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LoRaWAN Security Issues• Root Key is LoRaWAN Master key• Root Key is the LoRaWAN principal key used to derive allother cryptographic keys
• Root Key issues : The root key value remains the same
throughout the device's lifespan, implying that its crypto
period exceeds the recommended value• Session Key is a derivation key used to securecommunication and payload transmission.
• Session Key issue: LoRaWAN apply the same session
key to secure multiple communication sessions – Keyrepetition leads to data leakage when it is compromised.
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LoRaWAN Security Issues• Cryptoperiod of Root Key →It must bechanged at least once a year (NISTSpecial Publication 800-57 Part 1 Rev. 5)• Root Key = LoRaWAN’s Master key
NIST SP 800-57• Cryptoperiod of Session Key →NIST recommends that the session
key should be applied only once inevery communication or should be
unique to each session (NISTSpecial Publication 800-57 Part 3Rev. 1)
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NIST SP 800-57

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Section 2

Novel Secure Root Key Updating Scheme for LoRaWANs Based on
CTR_AES DRBG 128• The involved Entities
1. ED
2. JS

• Scheme❖ Time-driven:
Periodic Update• Phases❖ Phase-1: Initialization at ED❖ Phase-2: Root Key update process at JS• Communication Protocol❖ New_Join-request & New_Rejoin-request❖ New_Join-accept & New_Rejoin-accept

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Pict 3.1 General Architecture of LoRaWAN’sroot key update• Root Key Update Algorithm❖ CTR_AES DRBG 128 bit❖ Input: Key + Counter generated by RBG
module complied to FIPS 140 standard❖ Output: New Root Key13

Section 2Phase 1: Initialization Process of Root key Update

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Section 2

Phase 2: Root keyUpdate Process• 𝑁𝑒𝑤_𝑅𝑜𝑜𝑡_𝐾𝑒𝑦=𝐶𝑇𝑅_𝐴𝐸S
𝐷𝑅𝐵𝐺_128𝑏𝑖𝑡𝑠 (𝐾𝑒𝑦,𝑁𝑜𝑛𝑐𝑒_𝐶𝑜𝑢𝑛𝑡|𝐷𝑒𝑣𝑁𝑜𝑛𝑐𝑒)or• 𝑁𝑒𝑤_𝑅𝑜𝑜𝑡_𝐾𝑒𝑦=𝐶𝑇𝑅_𝐴𝐸S
𝐷𝑅𝐵𝐺_128𝑏𝑖𝑡𝑠(𝐾𝑒𝑦,𝑁𝑜𝑛𝑐𝑒_𝐶𝑜𝑢𝑛𝑡|𝑅𝐽𝐶𝑜𝑢𝑛𝑡1)

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Section 2.1

Algorithm Design of The CTR_AES DRBG 128-bits• Input Parameter: Key + Counter, Gabungan Nonce_Count with
DevNonce/RJCount1• Source of input parameter (Key + Nonce_Count): RBG appoved by FIPS 140• Reseed counter dijalankan setiap 2^16 – 1• Internal state (block encrypt) : CTR_AES 128-bits• Algorithm output: New_Root_Key
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Section 2.2

General Architecture: Session Key Update Scheme• Proposed Approachbased on Truncated Photon-256❖ Time-driven: Periodic Update• Entities involved in the scheme:❖ End Device (ED), Join Server (JS), NetworkServer (NS), Application Server (AS)• The scheme consists of three stages
1. INIT_Stage occurs at ED
2. SKey_MatPrep occurs at JS
3. NSKey_Update & AS_KeyUpdate occur at ED,NS, AS• Communication Protocol between ED-JS❖ New_Rejoin-request❖ New_ReJoin-response❖ New_Rejoin-ack• Communication Protocol between JS-NS & JS-AS❖ JN-SKeyMat & JA-SKeyMat❖ JN-accept & JA-accept❖ JN-response & JA-response

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Communication Session between ED-JS, JS-NS & JS-AS

Between ED-JS

Between JS-NSSection 2.2

Between JS-AS19

Truncated Photon-256 Algorithm of
NSKey_Update & ASKey_Update➢NSKey_Update• FNwkSIntKey=Trunc_128 (Photon-256 (MPNet||0x01||Te||NetID||DevEUI));• SNwkSIntKey=Trunc_128 (Photon- 256 (MPNet||0x03||Te||NetID||DevEUI));• NwkSEncKey=Trunc_128 (Photon-256 (MPNet||0x04||Te||NetID||DevEUI));➢ASKey_Update• AppSKey=Trunc_128 (Photon- 256 (MPApp||0x02||Te||AppID||DevEUI)).

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Research overview and Conclusions

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N. Hayati, K. Ramli, S. Windarta, M.
Suryanegara, “A Novel Secure Root Key
Updating Scheme for LoRaWANs Basedon CTR_AES DRBG 128,” IEEE Access, vol.
10, pp. 18807–18819, 2022,
Doi: 10.1109/ACCESS.2022.3150281.

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N. Hayati, S. Windarta, M. Suryanegara, B.
Pranggono and K. Ramli, "A Novel Session
Key Update Scheme for LoRaWAN," in IEEEAccess, vol. 10, pp. 89696-89713, 2022,
Doi: 10.1109/ACCESS.2022.3200397

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23THANK YOU
International Conference on ASEAN JAPAN Cybersecurity Community 2023