Because it's already working before you even open an app. Discover the hidden system layer of your smartphone.
What is Rated
what is firmly anchored in the device – operating system and hardware. Apps, browsers, cloud services etc. can be freely installed and uninstalled. They therefore escape objective assessment.
What is Evaluated
13 criteria in 2 categories – 3 for the operating system (open source tracking, bootloader), 10 for hardware (from baseband modem to built-in device identification).
How it is Weighted
the "Operating System" category is weighted at 30% and the "Hardware" category at 70%. Within the categories, the rating criteria are also weighted so that the sum equals 30% and 70% respectively.
Points Distribution
range from 0 to 5 – with 0 = complete lack of transparency and 5 = complete transparency. The score contribution of a single rating criterion is calculated as follows: Points per criterion / 5 x weighting. The overall score is obtained by summing the score contributions of all individual criteria.
Status
Solved – complete transparency possible
Solvable – in development
Unsolved – currently complete lack of transparency
Category A — Operating System
Max. 30%| Criterion | Weight | What is Rated | Status |
|---|---|---|---|
| OS Open Source | 12% | Is the operating system fully open source and independently auditable? Why relevant: Only open code can be checked for backdoors — proprietary systems must be blindly trusted. Goal: The entire operating system is publicly viewable and auditable by independent security researchers — no hidden code, no blind spots. | Solved |
| Built-in Telemetry | 10% | Does the OS send data to the manufacturer by default? Is complete opt-out possible and verifiable? Why relevant: Android sends all data to Google every 4.5 minutes in default state — even with the display turned off. Goal: The device sends no data to the manufacturer or third parties in its default state. Every data transfer is documented, deactivatable and verifiable. | Solved |
| Bootloader Unlockable | 8% | Can the device be flashed with an alternative operating system without manufacturer restrictions? Why relevant: A locked bootloader makes you permanently dependent on the manufacturer — you cannot replace the pre-installed system. Goal: You can install an alternative operating system at any time — and securely lock the bootloader afterwards. | Solved |
Category B — Hardware & Chips
Max. 70%| Criterion | Weight | What is Rated | Status |
|---|---|---|---|
| Baseband / ModemConnects you to the mobile network — but who else is listening? | 22% | Transparency and openness of the cellular chip (the chip that transmits calls and data over the mobile network). The modem has its own proprietary operating system and communicates directly with the network — bypassing the OS. Why relevant: No consumer device today has an open modem. It is the biggest blind spot in any smartphone. Goal: The mobile modem is fully documented and open source — its behavior is comprehensible to users and researchers. | Unsolved |
| Hardware Kill-SwitchesCan you really turn off the camera or microphone? | 12% | Physical switches that disconnect the camera, microphone and WiFi from power — independent of the operating system. Why relevant: Software deactivation can be bypassed. A physical switch cannot. Currently only available on the Purism Librem Phone. Goal: Camera, microphone and WiFi can be physically disconnected from power via a switch — independent of software and operating system. | Solvable |
| Firmware Blobs / Drivers | 8% | Proprietary firmware components (closed software modules) in graphics, camera, WiFi. Why relevant: This code runs on your device and is delivered directly by the chip manufacturer — without the possibility of verification by the user, the phone manufacturer or independent security researchers. Goal: All driver components are open source and independently audited — no hidden manufacturer code on your device. | Solvable |
| WiFi & Bluetooth ChipTransmits signals permanently — even when you're not surfing. | 7% | Are open drivers available? Is the chip firmware transparent and auditable? Why relevant: WiFi and Bluetooth chips communicate permanently with the environment — without open firmware, it's unclear what is being transmitted. Goal: WiFi and Bluetooth chips work with open source firmware — every signal transmission is documented and verifiable. | Solvable |
| TEE / Secure EnclaveProtects your data — or the manufacturer's? | 6% | The security chip (isolated chip for keys, biometrics and payments) manages the most sensitive data on your device. Usually proprietary and not auditable. Why relevant: Whoever controls the TEE controls your fingerprints, passwords and payment data. The OpenTitan project is working on an open alternative. Goal: The security chip is open source and independently audited — you know exactly who has access to your keys and biometric data. | Solvable |
| NFC-Chip | 5% | Is the NFC chip openly accessible or locked (e.g. only Apple Pay)? Kill-switch possible? Why relevant: NFC chips work within a few centimeters distance. Without a kill-switch, your device can be read out in subways, shopping centers or at controlled doors — without you noticing. Goal: The NFC chip can be completely disabled and is openly accessible for all applications — no manufacturer locks. | Solvable |
| Power Management IC (PMIC) | 4% | Controls the power flow to all chips in the device. Completely undocumented — nobody actively researches it. Why relevant: The PMIC decides which chip gets power when. In theory, a manipulated PMIC could secretly activate individual chips — even if the OS has disabled them. Currently still a pioneer field. Goal: Every chip only receives power when you want it — fully documented and controllable. | Unsolved |
| Hardware-ID IMEI | 3% | The IMEI uniquely identifies your device on the mobile network — a permanent, unchangeable fingerprint. Why relevant: With the IMEI, your location can be tracked even without a SIM card. Randomization is legally restricted. Goal: The device identifier is automatically randomized with each network switch — no permanent fingerprint on the mobile network. | Unsolved |
| Hardware-ID MAC / Bluetooth | 2% | The MAC address uniquely identifies your device on WiFi networks. Software-side randomization is possible (e.g. GrapheneOS). Why relevant: Without randomization, shopping centers, airports and public networks can permanently track your movements. Goal: The MAC address is randomly selected with each new connection — no WiFi network can track you across locations. | Via Software |
| IMU / Motion Sensors | 1% | Gyroscope and accelerometer — actually for navigation purposes. Why relevant: Studies show that typing patterns and movement profiles from sensor data can be used for unique identification. Software-side randomization is possible. Goal: Sensor access is granularly controllable — your typing and movement behavior remains private. | Via Software |
The Transparency Scale
How Much Your Smartphone Knows About You
Devices in the red area collect data about you – without your knowledge or influence. Knowledge is one-sided: on their side.
Devices in the green area make visible what's happening – and let you intervene. You decide what's shared. The greener, the more control is in your hands.
0%25%50%75%100%
iPhones
~17%
Closed system. No control for users.
Samsung
~36–40%
Good hardware, proprietary system with telemetry.
freifon
53–64%
Open source, no telemetry, more control.
Check now what your device really reveals about you.
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