Ethereum: A Turing-Complete Cryptocurrency
ethereum.org
ethereum.org
1. What protection against non-halting?
contracts are "funded" upon creation, and by those who issue transactions to the contract. if there are specific fees required by the contract to perform an action, it must be enforced by the contract itself. the cost of computation will eventually exhaust the contract's funding it fails.
2. what are the long-term economics? (i.e. is coin supply unlimited or limited and at what rate of decay)
line 90- other coins will be issued so the initial money supply is 15000 times the contributed BTC amount, with 0.25x (i.e. 16.67%) to the founders, same amount to fund the Etherium organization. Division of BTC not specified.
- the mining reward will be 1/3 of the initial supply, per year, perpetually (i.e. 1/2 the contributor's reward.) So the money supply increases linearly.
3. if a person's only goal was to use the blockchain to store data, what would be cost per byte, and is there a max rate?
line 385 to 399
- storage of a "data item" in contract memory costs 100x where x = floor(10^21 / floor(difficulty ^ 0.5))
- don't see the limit/cost of data items bound to transactions as per transaction definition on line 133
anyway it takes courage to name a currency after a drug like ether.
From Thesaurus: "ether - the fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies"
Perfect name.
Ethers are also a group of rather common organical compounds in chemistry. This is the page Wikipedia gives you when searching "Ether", as gateway allures to. Apparently, a specific compound of those (diethyl ether) can be used as a drug. Seems rather unlikely to me that people would connect the name to the drug first.
Appologies to Hunter S. ThompsonThe transaction fee is determined based on the number of computational steps in the contract. My understanding is that, if the contract has not halted by the time the transaction fee has been "spent", then the transaction is rejected.
So maybe it's Vitalik Buterin, one of the more interesting cryptocurrency thinkers out there. Hmm.
I think that Dagger has serious issues. First, the spec is buggy: the text says that eight bottom-level nodes are hashed together, but the pseudocode only uses four. Second, it does not require 512MB per thread; it requires 512MB of write-once, read-many-times memory, shared by all threads; this property seems to be asking for a rather large ASIC (or a smaller ASIC backed by some multi-port SRAM) to have a huge advantage.
Also, what's up with the choice of secp256k1? It's at least less likely to be backdoored by evil choice of parameters than, say, P-256, but there are many better choices out there (e.g. curve25519 or some of its larger variants). Those better variants have the big advantage (especially in this application) of having faster verification operations.
(The fastest-to-verify option would probably be plain ol' RSA, but signatures are rather large.)
(Saw comments that the site went down and still had it loaded on my machine)
"As a result, we have a cryptocurrency protocol whose codebase is very small, and yet which can do anything that any cryptocurrency will ever be able to do."
Line 283 of http://pastebin.com/NCGRv74u
http://fusion.net/modern_life/story/ethereum-bitcoin-currenc...
BTW, also contact me if you want help investing in alt-coins. I'm going to start an alt-coin hedge fund.
http://webcache.googleusercontent.com/search?q=cache:0RAOB-M...
I don't see anything regarding compute rewards here. It's all about the mining PoW. If all nodes are validating the Turing-complete scripts, and only the miners are getting paid, how does that work? What am I missing?
Cuckoo Cycle is a new proof of work system with the following features
1) proofs take the form of a length 42 cycle in the Cuckoo graph, so that verification only requires computing 42 hashes.
2) the graph size (number of nodes) can scale from 1x2^10 to 7x2^29 with 4 bytes needed per node, so memory use scales from 4KB to 14GB
3) running time is roughly linear in memory, at under 1s/4MB
4) there is no time-memory trade-off, and memory access patterns are the worst possible, making the algorithm constrained by memory latency
5) it has a natural notion of difficulty, namely the number of edges in the graph; above about 60% of size, a 42-cycle is almost guaranteed, but below 50% the probability starts to fall sharply
the program could be rewritten not to use bit 31 as a flag, and then you could use as many as 2^32-1 nodes, but that's not neatly expressible as MULT*2^SHIFT with few digits.
The ethereum proposal is the most technical yet. Hopefully it sets a new minimum bar in the market for crowd-funded vaporware (I'm highly skeptical of them all).
Edit: maybe the modification strategy could provide some 'proof-of-steak' protections, without burdening the system with excessive early adopter advantages.
[0] http://dx.doi.org/10.1109/IPDPS.2004.1303105
wiki here
>It is purposefully not Turing-complete, with no loops.
What am I missing? Is the idea that without loops the transaction size can be used to estimate the computation required without actually performing it, and thus the appropriately sized transaction fee required?
Bear in mind that in the Bitcoin design it's not just miners who have to run scripts, it's all nodes, yet fees accrue only to the miners. Bitcoin does use fees to try and make computationally expensive transactions financially expensive as well, but that's just a basic antiflood mechanism, the fees don't actually get collected by those doing the work.