Related to his work on the Services_Trackback PEAR Package he worked on, Tobias Schlitt looks today in this new blog post at some of his more recent thoughts on trackback spam.

It's been a long while since I worked on my PEAR package Services_Trackback, mainly because I was much too busy with work and university. Nevertheless I made up my mind about how to solve the problem of the so-called trackback spam.

Taking for granted, that the idea should work, there are 2 main questions to answer: "How can a sender of a trackback be identified?" and "If and how must the trackback standard be changed to support the identification?" For question #1 there is a simple answer (IMHO): PGP/GPG (further on referred to as GPG, for simplicity).

He suggests that since there is already a "trust relationship" inherent in the system, a PGP/GPG setup might be the most flexible, easy-to-use, constantly adapting method for preventing one of the banes of bloggers' existences...