I had forgotten about them. I have looked into digital cash a number of times, and think the idea of digital bearer bonds has some real merrit. That said, well, real bearer bonds exist to close gaps in the cash system (traveler's checks, Gift cards), so I don't see any reason to be surprised that digital ones wouldn't be used to close gaps in digital systems.

I always liked the Digital cash protocol outlined in "Applied Cryptography" that allowed for a person to buy "money orders" that were not anonymous to buy, but utterly anonymous to actually use, unless the purchaser tried to double spend them.... in which case, the issuer could use the two spent orders to discover the identifying information of the cheat.

But..... getting back to history.... I think it shows that history does matter. Yes, technically speaking the main difference between bitcoin today, and what bitcoin would have been 10-15 years ago is the target hash would have to be much higher

Without having Satoshi here and "in character" (if the speculation is true) to say what the full motivations and inspirations were, its hard to say exactly what spawned it...however....

The time we are talking about was not just before EGold ran into problems, before DigiCash failed but also, before Napster was brought down. Before its direct descendants were slain. Each of these things can be seen as projecting requirements on any new system that doesn't want to repeat the mistakes of the past....

There is definite novelty in the way the peices are put together (if not the peices themselves) however, it is also the product of the problem that it was trying to solve, a problem that was posed by these failures. it is, their logical successor.

Actually if you look at Wei Dai's b-money or Nick Szabo's Bit Gold proposals, both from the 90's, you see a lot of the ideas of Bitcoin.

b-money:
b-money used proof of work in a different way for money creation, but transfers are just like Bitcoin.

Bit Gold:

Bit Gold comes closer to the creation concept of Bitcoin. The way the blocks chain together is much like Nick's challenge problems.

Signed attestations running in secure hardware. Yup, way to make it cheap, available, and easy to implement and boot strap

Classic over-engineering. I think its pretty clear that the current success of bitcoin is because it ends up being so much simpler. You don't need specialized hardware to mine (that can come later). Anyone can pretty easily run it, it simply doesn't require a central authority, aside from whichever client people decide to use.

It may take more time, effort, and resources to over-engineer, but that doesn't mean that simplicity is easy. Simplicity often comes from looking at a bad solution or three and seeing why they suck so bad.

That's way too low a rate for me but I can throw out some freebies from off the top of my head.  From what I remember, most of the ideas that bridge the gap between proof-of-work functions to fight spam (e.g. hashcash) and creating a general currency and payment system like BitCoin were developed on a closed list I was on back on the 1990s, so it may be hard to recreate that history based just on what's published on the Internet.   It was a spin-off of the cypherpunks list.  Szabo was quite knowledgeable about the history of money and often wrote about how gold was insecure, and paper money even worse, and he wrote proposals for digital currency that mimicked what he called "unforgeable costliness" of gold rather than of paper money because gold doesn't rely for its value on a trusted third party.    And Wei Dai was also on that list writing about b-money, which I personally don't really understand except that its goals seem to be basically the same.   Szabo and Dai don't cite each other so there is some sort of soap opera going on there. These ideas were in contrast to credit cards, ACH, Chaum's e-cash, PayPal,  etc. that try to copy the characteristics of various kinds of paper money or credit and in particular rely on monolithic trusted parties.  If you read the following carefully the main breakthrough ideas between hashcash and BitCoin, especially Byzantine fault tolerance and transaction signature chains to solve the double-spending problem, are described in a more generalized context:

http://szabo.best.vwh.net/securetitle.html

This also gives us a useful way to think about the signature chains in BitCoin: as describing ownership of bits, which ownership can be transferred by digital signatures.

None of this AFAIK was actually coded and released until Finney and Nakamoto.