Ok, I don't remember a lot about this, but it was rather intriguing.
From what I recall, it was written in such a way that it must have been published as a serial; multiple climaxes and denouements.
Elements I remember:
- Someone was using various high-level secrets to trade for other high-level secrets... VERY high-level.
- One of the secrets was how legitimate currency was verified electronically. It ended up being something about creases or marks at very specific locations.
- At one point the hero, or one of his people, got arrested to make contact with someone inside a prison of some sort; they then bought his way back out, using paper that was properly 'tweaked' using the above secret.
- The final secret at the end was some form of physical immortality, achieved by some nasty method. The hero, as I recall, ends up killing the person who was behind this, and who had made use of that last secret.
Any ideas? I read it maybe 5 years ago, but I believe it was from a VERY old book.