Topic: Hash tree and hash algorithms: can a hash tree use multiple hash algorithms? (Read 3504 times)
December 31, 2012, 01:08:05 AM
Right, I guess I can just use the block hashes themselves then. Reading up on it, it doesn't seem like multiple hash algorithms should be a problem, although I don't think it's been implemented before (PPC uses only SHA256 as a hash function; the proof of stake blocks are just very low difficulty apparently).
December 30, 2012, 03:16:10 PM
As dree12 pointed out you don't want to use nonces. Super easy to game. Would just require a miner program which skips certain undesirable nonces.
You could simply use the block hashes which if blocks are "difficult" to construct should be relatively psuedo-random. It would be possible to game the output but that would require throwing away undesirable blocks. Unlike nonces they have real value.
So you have a couple options. The simplest would be to just use the x least significant digits of the various block hashes in the algorithm which determines the algorithm for the next block.
You could simply use the block hashes which if blocks are "difficult" to construct should be relatively psuedo-random. It would be possible to game the output but that would require throwing away undesirable blocks. Unlike nonces they have real value.
So you have a couple options. The simplest would be to just use the x least significant digits of the various block hashes in the algorithm which determines the algorithm for the next block.
December 30, 2012, 02:45:36 PM
Hi,
I'm working on a bitcoin fork right now and I'm trying to figure out something related to data structures.
I want to develop a blockchain (hash tree) whose algorithm for hashing subsequent blocks is determined as a function of the nonce of the 0th, 0th + c, 0th + 2c, ... , etc block (leaf) where c is a constant. I assume that the nonce values are pseudorandom and non-predictable, but I don't know if that's actually true.
Which leads to the question: Can I compose a hash tree like this? What kind of problems do you think I'll run into, and are they impossible to overcome? I want to see if anyone knows the answer to this before I begin trying.
I don't know if this kind of hash tree has a name or not either, or if it's been implemented before. I guess it might be called a polymorphic hash tree.
Nonce values may not necessarily be secure. Because the miner can selectively choose nonces without a significant impact on hash rate, intelligent miners will choose the most self-beneficial nonce values.I'm working on a bitcoin fork right now and I'm trying to figure out something related to data structures.
I want to develop a blockchain (hash tree) whose algorithm for hashing subsequent blocks is determined as a function of the nonce of the 0th, 0th + c, 0th + 2c, ... , etc block (leaf) where c is a constant. I assume that the nonce values are pseudorandom and non-predictable, but I don't know if that's actually true.
Which leads to the question: Can I compose a hash tree like this? What kind of problems do you think I'll run into, and are they impossible to overcome? I want to see if anyone knows the answer to this before I begin trying.
I don't know if this kind of hash tree has a name or not either, or if it's been implemented before. I guess it might be called a polymorphic hash tree.
For example, I can write code to increase the nonce by 5 rather than simply incrementing it, to ensure that the nonce is divisible by 5. Nonce values are only non-predictable if there is no financial incentive to make them predictable.
December 30, 2012, 02:35:13 PM
I think PPC has multiple algorithms: PoW and PoS
December 30, 2012, 02:22:40 PM
Hi,
I'm working on a bitcoin fork right now and I'm trying to figure out something related to data structures.
I want to develop a blockchain (hash tree) whose algorithm for hashing subsequent blocks is determined as a function of the nonce of the 0th, 0th + c, 0th + 2c, ... , etc block (leaf) where c is a constant. I assume that the nonce values are pseudorandom and non-predictable, but I don't know if that's actually true.
Which leads to the question: Can I compose a hash tree like this? What kind of problems do you think I'll run into, and are they impossible to overcome? I want to see if anyone knows the answer to this before I begin trying.
I don't know if this kind of hash tree has a name or not either, or if it's been implemented before. I guess it might be called a polymorphic hash tree.
I'm working on a bitcoin fork right now and I'm trying to figure out something related to data structures.
I want to develop a blockchain (hash tree) whose algorithm for hashing subsequent blocks is determined as a function of the nonce of the 0th, 0th + c, 0th + 2c, ... , etc block (leaf) where c is a constant. I assume that the nonce values are pseudorandom and non-predictable, but I don't know if that's actually true.
Which leads to the question: Can I compose a hash tree like this? What kind of problems do you think I'll run into, and are they impossible to overcome? I want to see if anyone knows the answer to this before I begin trying.
I don't know if this kind of hash tree has a name or not either, or if it's been implemented before. I guess it might be called a polymorphic hash tree.
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