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Identiverse 2021 - Cryptographic Protocols for Machine Identities and Credentials

Mrinal Wadhwa
June 23, 2021
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Identiverse 2021 - Cryptographic Protocols for Machine Identities and Credentials

Mrinal Wadhwa

June 23, 2021
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  1. IoT will have an economic impact between $4 trillion and

    $11 trillion, by 2025. Source: McKinsey & Company
  2. JUNE 2021 1. Implicit trust in network boundaries. Source: Dragos

    - Industrial Control Systems, CyberSecurity, Year in Review 2019 & 2020 Root causes
  3. JUNE 2021 1. Implicit trust in network boundaries . 2.

    Lack of end-to-end data integrity and con fi dentiality. Root causes
  4. Least Privilege. Principle of Every program and every privileged user

    of the system should operate using the least amount of privilege necessary to complete the job.” — Jerome Saltzer, Communications of the ACM, 1974
  5. The phone may not be online all the time so

    the service also caches this data to deliver it later … Heart Rate Monitor Heart Rate Service 80 bpm Heart Rate Application
  6. Initiator Responder Shared Secret Shared Secret M1 M2 M3 The

    shared secret is then used as a key in Symmetric Key Cryptography to maintain con fi dentiality and integrity of application data. Application Data - Authenticated Encryption The entities involved use Public Key Cryptography to authenticate each other and agree on a shared secret. Authenticated Key Exchange D Secure Channel
  7. THREAT DESIRED PROPERTY S Spoo fi ng identity Identi fi

    cation, Authentication T Tampering with data Integrity R Repudiation Non-repudiability (some applications desire the opposite) I Information disclosure Con fi dentiality D Denial of service Availability E Elevation of privilege Authorization Note that this model is very high level, there is massive amounts of nuance in dealing with each of the rows. The STRIDE threat model can help us evaluate every message.
  8. Coming back to our heart rate solution, for secure communication

    … Heart Rate Monitor Heart Rate Service Heart Rate Application
  9. Heart Rate Monitor Heart Rate Service Secure Channel We setup

    a secure channel between the monitor and the service. Heart Rate Application
  10. Heart Rate Monitor Heart Rate Service Secure Channel Secure Channel

    And another secure channel between the phone and the service. Heart Rate Application
  11. Heart Rate Monitor Heart Rate Service Transport Layer Security Transport

    Layer Security Since these devices have direct access to the internet, with TLS … Heart Rate Application
  12. Heart Rate Monitor Heart Rate Service 80 bpm Transport Layer

    Security Transport Layer Security Heart Rate Application
  13. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… Transport

    Layer Security Transport Layer Security Heart Rate Application
  14. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… 80

    bpm Transport Layer Security Transport Layer Security Heart Rate Application
  15. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… 80

    bpm 0x8621f842… Transport Layer Security Transport Layer Security Heart Rate Application
  16. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… 80

    bpm 0x8621f842… 80 bpm This type of setup is industry best practice. Transport Layer Security Transport Layer Security Heart Rate Application
  17. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… 80

    bpm 0x8621f842… 80 bpm But even when we manage to setup the channels correctly the data is still exposed to the service. 
 The service doesn’t need to know the contents of the message to route and cache messages (its primary job). Transport Layer Security Transport Layer Security Heart Rate Application
  18. Route/Cache sensor data, alerts and videos. Camera Door Bell Camera

    Door Bell Application Camera Door Bell Service
  19. Gateway Flood Warning Sensor Multiple transport protocols in the path

    of one message. TCP TCP Flood Monitoring System Sensors Vendor’s Service LPWAN
  20. Secure Channel implementations are usually tightly coupled with the length

    and duration of the underlying transport layer connection.
  21. JUNE 2021 1. Implicit trust in network boundaries . 2.

    Lack of end-to-end data integrity and con fi dentiality . 3. Lack of mutual authentication. Root causes
  22. JUNE 2021 1. Implicit trust in network boundaries . 2.

    Lack of end-to-end data integrity and con fi dentiality . 3. Lack of mutual authentication . 4. Poor management of keys and credentials. Root causes
  23. Initiator Responder Shared Secret Shared Secret M1 M2 M3 The

    shared secret is then used as a key in Symmetric Key Cryptography to maintain con fi dentiality and integrity of application data. Application Data - Authenticated Encryption The entities involved use Public Key Cryptography to authenticate each other and agree on a shared secret. Authenticated Key Exchange D Secure Channel
  24. Heart Rate Monitor Heart Rate Service 80 bpm 0x217c5111… 80

    bpm 0x8621f842… 80 bpm But even when we manage to setup the channels correctly the data is still exposed to the service. 
 The service doesn’t need to know the contents of the message to route and cache messages (its primary job). Transport Layer Security Transport Layer Security Heart Rate Application
  25. THREAT DESIRED PROPERTY S Spoo fi ng identity Identi fi

    cation, Authentication T Tampering with data Integrity R Repudiation Non-repudiability (some applications desire the opposite) I Information disclosure Con fi dentiality D Denial of service Availability E Elevation of privilege Authorization Note that this model is very high level, there is massive amounts of nuance in dealing with each of the rows. The STRIDE threat model can help us evaluate every message.
  26. JUNE 2021 Device Enrollmen t Leased API access token s

    Firmware Updat e Find my lost device …
  27. JUNE 2021 Zero Knowledge Proofs Mozilla is using Non-Interactive Zero

    Knowledge Proofs to collect telemetry from the Firefox browser without collecting any private browser usage. A large subset of IoT use cases is telemetry collection.
  28. JUNE 2021 Federated Learning Google Keyboard learns out-of-vocabulary words on

    mobile phones without exposing sensitive text to servers. 
 Connected sensors could similarly learn to improve accuracy while preserving privacy.