Data compression, 1980s-style–and why PKZIP won

My employer has me doing some very gray-hat work that I don’t want to describe in detail, because the information has a tremendous potential for misuse. But suffice it to say I’ve been trying to send data places the data shouldn’t go, and I tried to do it by going all 1987 on it by compressing the data with obsolete compression programs. Ever heard of security by obscurity? I was trying to bypass security by using obscurity. In the process, I learned why PKZIP won the compression wars.

This is a very good reason to deploy 64-bit Windows 7 in your enterprise, because these obsolete 16-bit compression programs won’t run under Windows 7. I found that out the hard way once I got the data through to the other side and tried to decompress it. Oops. But tell me, what’s the legitimate business need to run 16-bit DOS applications in 2014? Maybe in a sizable company, one or two people have that need. Find some other way to accommodate them, and make life difficult for attackers, OK?

I say this because I was able to get the data where I wanted it to go. What I found was that once I got the data where I wanted it, and moved to a machine that could run my 16-bit decompression program (back then the compressor and decompressor were often different programs), the data was corrupted more often than not.

Of course, in my BBSing days, it sure seemed like a lot of my downloads wouldn’t decompress correctly, or they’d decompress but the program wouldn’t run. I always blamed my modem and line noise, the bane of BBSing in days of yore. But, for some reason, after PKZIP came along and became popular, downloads worked a lot better. Then along came some other programs like LHARC and its cousins, and they were perfectly reliable too, and tended to compress better than PKZIP did. Naturally, I became a fan. If it’s better and doomed to fail, I always like it. PKZIP of course was the first one to be really reliable, so it quickly became entrenched, and its format won. You don’t see .LZH or .LHA files in the English-speaking world anymore.

So I guess I owe my modems an apology. In an environment free of line noise, those early, finicky, boy band-loving compression programs still failed too often for me to do what I wanted to do.

On a semi-related note, the algorithm could sometimes compress better than the original program could. Here’s some info on alternative ZIP utilities that compress better.

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