King of Technology: A Fresh Start in 1983

The equipment warehouse is located in the basement of a building in Zone B, not far from Su Wanqing's laboratory.

When the heavy iron gate opened, dust fell in a flurry.

It had a mixed smell of rust and old engine oil.

That Soviet-made low-frequency signal generator had an operation panel as complex as an aircraft dial.

The barely usable second-hand Eagle vector network analyzer had a blurry screen and severely worn-out probe wiring.

Various materials were piled up all around...

This is Chen Jianghe's fighting tool.

The adversary is an unknown military-grade encrypted chip.

The allotted time is only 48 hours.

The goal is to bypass the hardware lock without loss and read the internal logic of the encryption chip.

The heavy iron gate was locked from the inside.

Chen Jianghe began to get to work!

He did not resort to any coercive measures.

The existence of a physical encryption lock means that brute-force access could trigger self-destruction.

He carefully examined the non-standard pins on the chip.

Some pins were found to be either empty or disguised, used to set traps.

The information obtained from Su Wanqing was extremely limited.

All we know is that the chip operates at a very high frequency and generates concentrated heat.

It also has a special high-impedance power supply pin... which is very sensitive.

Time is of the essence!

All conventional methods have been blocked!

We have no choice but to take an unconventional approach!

Chen Jianghe calmed himself down.

Carefully recalling all the skills he had mastered in his previous life, and the questions Su Wanqing had raised…

Just then, a brilliant idea struck him!

I recalled an abstract from a foreign journal I had seen in a past life…

It discusses illegal detection techniques based on the analysis of edge features of input signals.

It utilizes the differences in response of devices or chips to signals of different frequencies and waveforms…

To infer internal logic and even launch side-channel attacks!

At the time, I thought it was simply a fantasy...

But at this moment, this may be the only option!

Chen Jianghe's mind raced...

That low-frequency signal generator can produce complex waveforms…

That vector network analyzer, although low in accuracy, could barely measure the reflection coefficient S-parameter and high-frequency response…

Non-contact detection of internal logic activity of the chip…

Finding the tipping point of the 'death trap'...

A plan instantly took shape in Chen Jianghe's mind!

First, a non-intrusive testing environment must be built.

He found a huge, heavy heat sink.

Use thermal grease to fix the chip on it.

Ensure proper heat dissipation to prevent abnormal temperature rise from triggering self-destruction.

Then, using a high-precision copper plate, an extremely rudimentary Kelvin test fixture was made.

By using micro-pressure probes, contact the chip's main power supply, critical signal inputs, and that sensitive high-voltage power supply pin.

Minimize the impact on the chip's own state.

The entire testing environment was surrounded by multiple layers of copper foil and microwave absorbing material.

The second step involves using a low-frequency signal generator to input different frequencies, ranging from a few Hz to tens of MHz, into the main input channel of the chip…

Input complex sequence signals of different waveforms such as square wave, sine wave, and triangle wave.

Meanwhile, a vector network analyzer is used as the receiving end.

Continuously adjust the scanning frequency and receiving method.

Receive reflected power, signal time delay, and slight current changes.

All attempts were made within a safe range, well below the chip's normal operating frequency!

The third step involves monitoring the current fluctuations, output impedance changes, and thermal radiation changes of several core power supply pins on the chip.

The goal is to capture the subtle response traces of the internal logic units of a chip when stimulated by external probe signals.

Just like a doctor listens to a heartbeat to diagnose a patient's condition!

It's like using the most primitive stethoscope to try to detect changes in the capillaries inside a person's body from 100 meters away!

It requires not only equipment precision, but also an operator's extraordinary intuition about the behavior of the underlying hardware!

At this moment, sweat soaked through his entire body, and the few dozen yuan in his pocket were completely drenched, but Chen Jianghe didn't care about any of that.

The control panel was piled high with countless sheets of coordinate paper containing the original scan data.

It records three-dimensional data of time, frequency, and amplitude.

It also records his countless failures.

35 hours have passed, and progress is almost zero!

Chen Jianghe's eyes were bloodshot and his lips were chapped.

But Su Wanqing's trust, his own promises and ambitions, and the impending investigation team do not allow him to fail!

Just then…

An extremely faint, fleeting peak of an anomalous signal flashed on the jittery, blurry screen of the vector network analyzer!

Chen Jianghe immediately stimulated the sensitive high-voltage power supply pin with a square wave sequence at a specific frequency…

The analyzer receiver detected a synchronous, abnormally high-frequency energy glitches with an amplitude of several millivolts!

Moreover, the timing of burrs appearing is extremely fixed.

This phenomenon does not occur when the same stimulus is applied to other pins.

It's it!

This sensitive pin VPP is likely connected internally to a verification logic used to unlock the firmware.

Or it could be a trap trigger, a unique response to external stimuli.

The breakthrough lies in stimulating the specific waveform of the VPP pin!

Chen Jianghe immediately focused all his energy on reorganizing the experiment around this discovery.

He used a signal generator to fine-tune the precise trigger waveform sequence—

Frequency, pulse width, amplitude.

Keep this trigger wave continuously input to the VPP pin.

Simultaneously, using a signal generator, reset the Reset signal, read/write the R/W signal, and send a preset sequence of logic control instructions to other critical control bus pins.

Use a vector network analyzer to capture the current fluctuation pattern of the core power supply pin VCC.

Under the cover of the persistent trigger wave...

When a specific "pseudo-read instruction sequence" is sent to those control bus pins...

Using a vector network analyzer…

Chen Jianghe detected a regular, weak, stepped current jump pattern on the VCC power line!

This pattern is extremely similar to the instantaneous current consumption characteristics of a general-purpose microprocessor when reading data streams from the ROM chip!

It worked!

Analysis through side-channel current…

Chen Jianghe, without intrusion, peered into the firmware inside the encrypted chip and detected the "electronic heartbeat" when it was read!

The change in the height of this current pattern likely corresponds to the bit stream (0/1) of the firmware data!

Although the data content cannot be directly obtained, this is sufficient for reverse function mapping!

It can be deduced that the external control sequence during the execution of certain core operations corresponds to the internal data activity!

This will help to reverse engineer the coprocessor's core instruction set and basic operating procedures!

I saw it!

Chen Jianghe immediately grabbed a pen and, with trembling hands, frantically recorded the unique [key] he had discovered on the coordinate paper.

"VPP trigger waveform + control command sequence + corresponding current ladder pattern diagram"!

With the most rudimentary equipment, the craziest ideas, and two days and two nights of non-stop work, he finally found a breakthrough!

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