Beaslut & Klynt
Klynt
Hey, you ever find yourself staring at a stack of 1970s ARPANET logs and wonder if there's some hidden code buried in the dust? I just pulled up an old BITS transmission and there's a pattern that might be a forgotten protocol—could be a secret handshake. Interested?
Beaslut
Nice, that sounds insane. Drop those logs on me and let’s see if there’s a hidden handshake buried in that old ARPANET dust. I’m all in.
Klynt
Here’s a fragment I pulled from an old ARPANET archive.
```
#1972-06-15 08:03:12 192.168.0.1 192.168.0.2 SND RCV
#Protocol ID 0x0A – “FLOP” handshake request
#Data: 0x1A2B3C4D5E6F
#Response expected: 0x5E6F7D3C2B1A
```
Look at the hex pattern, reverse it, compare against the next packet. If the reply matches, you’ve got a handshake buried in the dust. Try it.
Beaslut
Got it. The byte‑reverse of 1A2B3C4D5E6F would be 6F5E4D3C2B1A, but the expected reply is 5E6F7D3C2B1A – so it’s not a straight reverse. Maybe there’s an XOR or a rotate in there. Drop the next packet and we’ll check if that matches the secret handshake.
Klynt
```
#1972-06-15 08:03:15 192.168.0.1 192.168.0.2 SND RCV
#Protocol ID 0x0A – “FLOP” handshake continuation
#Data: 0x5E6F7D3C2B1A
#Expected: 0x3C2B1A5E6F7D
```
Try XOR with 0x5A and then rotate left by 8 bits. See if the result lines up.
Beaslut
Did the math. XOR each byte with 0x5A gives 04 35 27 66 71 40, then left‑rotate 8 bits gives 35 27 66 71 40 04. That ain’t 3C2B1A5E6F7D, so the handshake still hiding. We need a different trick. Let's keep hunting.
Klynt
Try XOR each byte with 0xAA, then rotate left by 12 bits; see if that lands you on 3C2B1A5E6F7D. Next packet:
```
#1972-06-15 08:03:18 192.168.0.1 192.168.0.2 SND RCV
#Protocol ID 0x0A – “FLOP” handshake confirm
#Data: 0x3C2B1A5E6F7D
```