DES key parity bit calculator

I was doing some reverse engineering and I could not find any tool which expands a 56 bit DES key into a 64 bit key with the parity bit included. Expanding the key is a pretty laborious process involving hex to bin conversions and plenty of manual counting. To add on, some online tools truncate ...

Bangladesh bank heist

The media initially attributed the hack to a couple of cheap second-hand $10 switches. However, according to further reverse engineering, this is not a snatch and grab but a full scale bank heist perpetrated by determined adversaries with resources at their disposal. Even if the bank had ...

Measuring Power Consumption

I have recently acquired an electricity usage meter off ebay and decided to measure the power consumption of some of my devices. For a device that costs just 15 SGD, it works wonderfully and can measure voltage, amperage and wattage. It is supposed to be able to calculate electricity cost once ...

Saturating 1Gbps bandwidth

My ISP recently gave me a free speed bump from 500Mbps to 1 Gbps. I wanted to test if it was possible to fully utilise the bandwidth on a single file transfer. Firstly, we need to look at the test file size. I settled on a roughly 500MB to 1GB file size to minimise the effect of TCP window size ...

Running HTTPS, SSH and VPN on port 443

A port can only be bound to one service at a time, which makes perfect sense since the OS cannot possibly know which application to route the packet to. However, protocols often have distinct signatures, for example the first few bytes of SSH is always SSH-2.0 while HTTP packets always start ...

ProtonMail: Technical prowess, Legal expertise and Guts

Technical prowess, Legal expertise and Guts. That is what you need to go up against a Nation State Adversary. We shall take the Apple vs US Government debate as an example. Apple obviously has the technical prowess to store the iPhone's PIN code securely. If it were easily retrievable, the ...