Admitted at JASSO Programs

The letter came at the worst possible time. Or maybe the best. I had just wrapped up the Ministry of National Education project (months of database schemas, integration meetings, and late nights cleaning educator data across provinces). I was exhausted. And then JASSO said yes.

JASSO (Japan Student Services Organization) offered me a position as a Guest Researcher at Kumamoto University. It was the opportunity I had been chasing. A chance to step into real academic research, to work alongside professors who published in journals I had only read from afar, to breathe the air of a proper research university. But acceptance letters do not come with pause buttons. There was no gap between the ministry project ending and Japan beginning. One chapter closed on a Friday, and the next opened on a Monday. No rest. No transition period. Just go.

The hardest part was not the workload. It was leaving my family. My wife and our 2 years old daughter. The life we had built together in Sidoarjo. Suddenly I was packing a suitcase for a country where I knew almost no one, where the language was foreign, where the culture operated on rules I had never learned. The airport goodbye was the kind that sits in your chest for weeks (the kind where you smile because crying would make it harder for everyone).

And then there was the mindset shift. For the past year, I had been a consultant (solving problems with deadlines, delivering systems that worked "good enough" for production, thinking in terms of deliverables and client satisfaction). Research is a completely different animal. There are no clients. There are no deadlines that matter more than correctness. The question is not "does it work?" but "why does it work?" and "can you prove it?" and "what does the literature say?"

I had to unlearn speed. In consulting, fast is good. In research, fast is suspicious. I had to unlearn certainty. In consulting, you present solutions with confidence. In research, you present hypotheses with humility. I had to unlearn the habit of skipping the "why" and jumping straight to the "how." Research demands that you sit with the question longer than feels comfortable.

Kumamoto itself was beautiful and quiet (a city rebuilt from volcanic ash and earthquake rubble, surrounded by mountains and hot springs). The university campus had a stillness that forced you to think. No traffic noise. No WhatsApp groups buzzing with project updates. Just you, the library, your supervisor's expectations, and the terrifying blank page of a research proposal.

The transition was brutal but necessary. Every night I video-called home, watching my wife's face on a pixelated screen, measuring the distance in time zones and missed dinners. But every morning I woke up knowing this was building something. Not a database. Not a system. But a version of myself that could think deeper, question harder, and contribute to knowledge rather than just consume it.

Looking back, the lack of rest between the ministry project and JASSO was actually a gift in disguise. It forced the transition to be abrupt, total, irreversible. There was no comfortable middle ground to linger in. I could not be half-consultant, half-researcher. I had to commit fully. And sometimes, that is exactly what growth requires (a clean break with no safety net).

The Research

My research at Kumamoto focused on VoIP security (specifically, analyzing security threats in the IAX2 protocol and detecting eavesdropping attacks). The full title: "Analysis of Security Threats for Deploying Secure IAX2 Protocol Based on VoIP Service: Case Study: Eavesdropping Detection."

VoIP was becoming the backbone of Next Generation Networks (voice and video streaming over the internet instead of traditional phone lines). One common way to deploy VoIP services was using Asterisk Server with the IAX2 protocol. IAX2 (Inter-Asterisk eXchange) is a protocol designed for connecting Asterisk servers to each other. It is efficient, handles NAT traversal well, and trunks multiple calls over a single connection. But it had security vulnerabilities that nobody was paying enough attention to.

Because IAX2 uses a single port (4569), an attacker can sniff or eavesdrop packets through that port. The eavesdropping attack was clearly demonstrated by Rajagopalan, using a tool called Unsniff. Beyond eavesdropping, other threats related to packet modification include: Denial of Service (where an attacker sends ACK packets to the IAX Server simultaneously, overwhelming it until it can no longer establish connections); and VoIP Spam (where an attacker sends fake personal information that prompts users to confirm, potentially leaking sensitive data). These threats can be prevented and handled if we know who is on the network and which computer is eavesdropping on IAX2 packets.

My work analyzed those vulnerabilities (mapping the threat landscape, proposing secure deployment mechanisms, and building a detection system for eavesdropping attacks). The idea was simple but critical: if someone is silently listening to your VoIP calls, can we detect it? And can we do it without degrading call quality?

This was where the consultant-to-researcher shift became real. In consulting, I would have just deployed a firewall and called it done. In research, I had to prove (mathematically, experimentally) that the detection method actually worked. I had to measure Quality of Service metrics, compare modified IAX2 implementations against baselines, and write it all up in a way that could withstand peer review.

Part of this research was later published and can be viewed at ResearchGate. It remains one of the works I am most proud of (not because it changed the world, but because it proved to myself that I could do rigorous serious academic work). That the kid who accidentally changed the admin password at a police station could grow up to analyze protocol-level security threats at a Japanese university.