Lines Matching +full:data +full:- +full:valid +full:- +full:time
1 .. _sensor-threat:
11 pressure in a pipe), which sends this data to an SoC running a
13 relays this sensor data to this service. The cloud service is also able
14 to send configuration data to the device, as well as software update
17 .. figure:: media/sensor-model.svg
28 This model also focuses on communicating via the MQTT-over-TLS protocol,
38 1. **The bootloader**. This is a small code/data image contained in
39 on-device flash that is the first code to run. In order to establish
43 programmed into the device, early in production [th-imboot]_.
52 [th-authrepl]_.
55 shall be done in a timely manner [th-timely-update]_.
60 [th-atomic-update]_.
64 are allowed to sign the certificate on the server. For cloud-provider
68 [th-root-certs]_, [th-root-check]_.
85 of code necessary shall have access to them. [th-secret-storage]_
87 5. **Current date/time**. TLS certificate verification requires
88 knowledge of the current date and time in order to determine if the
89 current time falls within the certificate's current validity time.
91 client to sign a message containing a time window that the token is
92 valid. Certificate validation requires the device's notion of date and
93 time to be accurate within a day or so. Token generation generally
94 requires the time to be accurate within 5-10 minutes.
96 It may be possible to approximate secure time by querying an
97 external time server. Secure NTP is possibly beyond the
99 time are denial of service (the device rejects valid certificates),
101 possible to trick the device into generating tokens that are valid in
103 certificate to be able to intercept this. [th-time]_
105 6. **Sensor data**. The data received from the sensor itself, and
109 7. **Device configuration**. Various configuration data, such as the
110 hostname of the service to connect to, the address of a time server,
111 frequency and parameters of when sensor data is sent to the service,
112 and other need to be kept by the device. This configuration data will
114 should be allowed only from authorized parties. [th-conf]_
117 device shall log information about security-pertinent events. IoT
121 resource-available environment. Types of events that should be logged
132 [th-logs]_
138 where data or assets are communicated between entities of the system.
190 configuration information. On resource-constrained devices, it is
203 data, and can range from having the sensor mounted on the same PCB as
210 DNS results or attempt man-in-the-middle attacks
214 service [th-all-tls]_. The TLS stack shall be configured to use only cipher suites
220 [th-tls-ciphers]_.
223 server shall be verified [th-root-check]_.
234 certificate chain has a valid signature path from a root
244 notion of the current time.
250 [th-tls-client-auth]_.
256 certificates can be self-signed, or signed by a CA. Since the
257 service provider maintains a list of valid certificates
262 ii. **Token-based authentication**. It is also possible for the
265 be transmitted in this packet. Instead, a token-based
275 modern, accepted cryptographic random-bit generator to generate
276 these random numbers. It shall use either a Non-Deterministic
279 by an entropy source within the SoC. Please see NIST SP 800-90A
280 for information on approved RBGs and NIST SP 800-90B for
281 information on testing a device's entropy source [th-entropy]_.
283 4. **Communication with the time service**. Ideally, the device shall
284 contain hardware that maintains a secure time. However, most SoCs in
286 an external time service.
288 describe the Simple Network Time Protocol that can be used to query
289 the current time from a network time server.
294 operation, re-provisioning, and destruction.
298 image, a device secret, and initial configuration data
299 [th-initial-provision]_. In
304 [th-initial-secret]_.
309 c. **Re-provisioning**. Sometimes it is necessary to re-provision a
312 data, as well as the cloud service data associated with the
316 [th-reprovision]_.
321 [th-destruction]_. Possibilities include:
343 .. [th-imboot] Must boot with an immutable bootloader.
345 .. [th-authrepl] Application image shall only be replaced with an
348 .. [th-timely-update]
351 .. [th-atomic-update]
354 .. [th-root-certs]
357 .. [th-root-check]
358 TLS must verify root certificate from server is valid.
360 .. [th-secret-storage]
364 .. [th-time]
366 date/time.
368 .. [th-conf]
369 The system must receive, and keep configuration data.
371 .. [th-logs]
372 The system must log security-related events, and either store them
375 .. [th-all-tls]
378 .. [th-tls-ciphers]
382 .. [th-tls-client-auth]
386 .. [th-entropy]
387 The TLS layer shall use a modern, accepted cryptographic random-bit
390 .. [th-initial-provision]
391 The device shall have a per-device secret loaded before deployment.
393 .. [th-initial-secret]
397 .. [th-reprovision]
400 .. [th-destruction]
408 See https://www.slideshare.net/kartben/iot-developer-survey-2018. As