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Hacker Claims To Have Decrypted Apple's Secure Enclave Processor Firmware (iclarified.com)
According to iClarified, a hacker by name of "xerub" has posted the decryption key for Apple's Secure Enclave Processor (SEP) firmware. "The security coprocessor was introduced alongside the iPhone 5s and Touch ID," reports iClarified. "It performs secure services for the rest of the SOC and prevents the main processor from getting direct access to sensitive data. It runs its own operating system (SEPOS) which includes a kernel, drivers, services, and applications." From the report: The Secure Enclave is responsible for processing fingerprint data from the Touch ID sensor, determining if there is a match against registered fingerprints, and then enabling access or purchases on behalf of the user. Communication between the processor and the Touch ID sensor takes place over a serial peripheral interface bus. The processor forwards the data to the Secure Enclave but can't read it. It's encrypted and authenticated with a session key that is negotiated using the device's shared key that is provisioned for the Touch ID sensor and the Secure Enclave. The session key exchange uses AES key wrapping with both sides providing a random key that establishes the session key and uses AES-CCM transport encryption. Today, xerub announced the decryption key "is fully grown." You can use img4lib to decrypt the firmware and xerub's SEP firmware split tool to process. Decryption of the SEP Firmware will make it easier for hackers and security researchers to comb through the SEP for vulnerabilities.
Suicide chips were common for a long time. And although effective are MUCH more trouble than they're worth.
For example, you'll lose ten times more "genuine" evidence (e.g. witnesses willingly handing their phones over for evidence, then the chip dying while in court storage) than anything you'll save on personal privacy.
Not to mention, get one duff battery/capacitor and one day your phone just stops working permanently with no possibility of restoration whatsoever.
This isn't an attack stopped by a suicide chip, either. You buy one device, let it wipe itself a thousand times in testing, get the key out of it eventually, and then you can attack ALL the security chips in ALL the phones way within your "day or two".
Plus, there's almost no way to ensure the timer is running. Isolate the suicide chip's clock (especially if it has to track real time and be running all the time) and you can pretty much stop it dead so it never gets to the point it can do anything about wiping the data.
Look into the old arcade stuff. Lots of old arcade games had suicide chips. Lots of them are still emulated. In many cases, people just ignored it and - like this - determined the keys in other ways (lots of arcade games have the equivalent of rainbow tables for their encryption in common emulators because the key itself was never found), in others they de-capped and imaged the chips while they were still working, which lets you basically pluck the stored data and logic of their semiconductors out of a microscope image of the silicon.
It's a lot of effort to go to, for a lot of risk. But what you describe is basically a proper TPM chip. I don't think anyone has ever successfully broken a TPM chip / keys, have they?
Given the assets available to the NSA, and their propensity to hide defects they find, I would not be surprised if this was already known to the NSA.