Bitcoin used Base58Check to encode the ip address and port[1]. The Base58 used by bitcoin was invented by Satoshi. Can you point to any specific code that used a similar IPv4 obfuscation scheme?
[1]https://github.com/trottier/original-bitcoin/blob/master/src/irc.cpp
I don't have any reference beyond the personal recollection of:
(1) getting false positives from the Cisco NIDS option in the Cisco IOS 12.something
(2) second hand accounts of similar false positives from Sandvine Inc. large-scale network management tools
You will find that lots of the code in the Bitcoin client isn't completely new, but an existing code reformatted and re-factored to use Satoshi's peculiar C++ style and his collection of C preprocessor macros.
My best recollection of base58 (and other similar nearly-human-readable schemes) is from license strings for artistic 3D modeling software from Softimage or Wavefront. They were working on transmitting those license strings via fax machines and have them correctly entered on computers with artistically designed fonts with indistinguishable characters (O vs. 0, 1 vs. l, etc.).