Chapter 79 - 33: The "Patch" in the Audio

Chapter 79: Chapter 33: The "Patch" in the Audio

"Yu Xian, can you send me this audio clip? I might... be able to analyze something using the lab’s equipment."

Yang Yiyi interrupted Yu Xian’s thoughts.

"Sure, thank you, Senior Sister. I’ll leave it in your hands then," Yu Xian replied. "I was just planning to find a friend in computer science to try and reverse-engineer it anyway."

Since there was no internet, Yu Xian had to send the audio file to Yang Yiyi via Bluetooth. He prepared to bid his senior sister farewell and head to the North Campus to find Wen Xiao, wanting to see if she had made any progress on analyzing yesterday’s login key.

"If you get the chance, help me look into the background of that industry fund too," Yu Xian added. "I have a feeling this audio might be related to your research results."

"Okay." Yang Yiyi looked worried. "But the rain is so heavy outside. Do you really have to go today?"

"Yeah. This matter... relates to some things happening to me, and it might concern the safety of many people."

Seeing him say this, Yang Yiyi didn’t try to stop him anymore. She pulled a pink power bank out of her pocket. "Then take this with you, keep your phone charged. If... if you encounter any danger, you can call me anytime."

"Okay... thank you, Senior Sister."

The two exchanged a glance at the entrance of the No.7 Dormitory. That single look made Yu Xian feel like he wasn’t fighting alone. He watched Yang Yiyi walk up the stairs before turning around and plunging headfirst into the curtain of rain.

From the South District to the North Campus, the deepest puddles already reached past his calves. Yu Xian felt like he was wading upstream against a rushing river.

Since there was no internet, he could only send Wen Xiao a text message. By the time Yu Xian arrived at the North Campus, Wen Xiao, bundled up in a down jacket and hugging her laptop, was already waiting at the turnstiles in the first-floor lobby.

"Yu Xian!" he heard her shout from afar. "You’re finally here... I was worried you had been washed away."

Her eyes widened when she saw Yu Xian looking like a drowned rat.

"Almost," Yu Xian joked, taking off his dripping raincoat as he walked.

Wen Xiao didn’t waste any words; she simply swiped her card and opened the gate. The two walked down a quiet corridor and took the elevator straight to a cubicle lounge area on the 12th floor. The place was completely empty, illuminated only by the dim yellow glow of the wall lamps. They sat down on the corner sofa; outside the floor-to-ceiling windows, the torrential rain poured down.

"Here, dry off first."

He then noticed a pink towel draped over the sofa, printed with a cartoon pattern he didn’t recognize. Yu Xian didn’t stand on ceremony. He wiped the rainwater from his face and hair, catching the scent of laundry detergent on the fabric.

"So, how is it? Did you figure out anything from that login key?"

"Yu Xian, that 45MB audio file you gave me... I reverse-engineered and decompiled it." Wen Xiao took a deep breath and tapped a few times on her keyboard. A complex spectrum analysis chart appeared on the screen. She had clearly divided the chart into three sections using different colors.

"TDI’s encryption algorithm is incredible. It really is a ’compressed file’ like you said. They used a dynamic polymorphic shell I’ve never seen before, but I managed to strip away the basic structure. Its payload is roughly divided into three parts."

"Payload?" Yu Xian didn’t quite understand the technical jargon.

"Right. They probably used a method called ’audio steganography’ to write hidden information into this audio by replacing a few sampling points in the white noise. Since human hearing isn’t sensitive to changes in the 1st to 4th bits, the human ear can’t detect anything at all. This genuinely meaningful hidden information is what we call a payload."

Seeing Yu Xian nod, Wen Xiao continued, pointing at the red waveform on the far left of the screen. "This is the first part. It makes up about 50% of the file, and it’s that piece by Schoenberg, *Piano Suite, Op. 25*. The one that uses the Twelve-tone Technique."

"What is it used for?" Yu Xian had been confused about the existence of this musical piece from the start. "Why this specific song?"

"I haven’t been able to figure that out yet. I’m guessing it might be to mask the data stream behind it. Or maybe this piece of music can trigger a certain state in the brain, like ’exchanging secret codes’—you know, saying ’Open Sesame’ or a secret password. I haven’t wrapped my head around it."

Yu Xian thought of a point. It was what Senior Sister Yang Yiyi had mentioned last time—the "firewall" that deceived the brain, which was the spindle wave. He wondered if it could be related to this.

"I heard from a senior sister in the School of Life Sciences that spindle waves ’evaluate’ and ’filter’ the threat level of sounds, acting like the brain’s ’firewall.’ Could the ’secret code’ you mentioned be this part?"

"Which senior sister? What did she say exactly?" Wen Xiao glanced at Yu Xian in confusion. "Could it be that the mathematical structure of the Twelve-tone Technique is similar to some underlying neural coding logic? I don’t get it... That sounds almost like a magic spell."

Yu Xian gestured for her to continue explaining and skip this part for now.

"The second part, let’s call it the ’black box.’ This part takes up about 45% and is also the heavily encrypted core. No matter what dictionary I used to brute-force it, I couldn’t crack its shell. There are no readable characters inside—it’s all gibberish. I even suspect that there’s no readable content in it to begin with..."

"No readable content?"

"Right, or rather, its data format simply can’t be read by human computers. It’s like trying to open a photograph with a text editor—all you’ll see is gibberish," Wen Xiao said, frowning as she pointed her mouse at the middle block of data.

"However," she said, shifting the topic, "the third part—the final part of the file—only makes up 5% of the information, and its encryption level isn’t nearly as high."