Academic Ethereum
-
Upload
gavofyork -
Category
Technology
-
view
948 -
download
1
Transcript of Academic Ethereum
ethereumethereum
Universal transaction ledger
Protocol determines:
order
meaningin terms of state change
ethereumethereum
Arbitrary state stored between transactions
Arbitrary state changes due to transactions
thus
Provides arbitration & enforcement for agreements with arbitrary mechanics
ethereumethereum
Transaction state-transition function
σ' = (σ, T, H)ϒ
Block reward function
σ' = Ω(σ, B)
Block state transition funtion
σ' = Π(σ, B)
where
B = (H, (T[0], T[1], …), U)
Π(σ, B) = Ω( ( (σ, T[0], H), T[1], H), B)ϒ ϒ
ethereumethereum
Address: public key (-ish)
System stores an account per address:
value
transaction count
state
code
ethereumethereum
Accounts
Create with codeNo private key (arbitrary public deterministically) chosen;
Thus no external access.
Create through sending fundsPossibility of private key (public assumed to be derived);
Full external access; no code possible.
ethereumethereum
Transaction state-transition (σ, T, H)ϒ
Resultant state depends on T type;
Creation or Message
ethereumethereum
Creation used to create account with associated code.
Message transfers value & invokes associated code.
ethereumethereum
Code execution:
Turing-complete instruction set machine;
stack-based architecture, with memory.
Code in separate ROM; and...
arbitrary-sized storage.
ethereumethereum
Message Invokation
Runs code in fresh instance of machine
Runs with contract's existing state
Passed byte-array input & can return output.
ethereumethereum
Creation
Creates a new contract
Runs initialisation code which returns the machine's code ROM
ethereumethereum
Transactions:
Cryptographically signed
Either create (includes init code);or message (includes destination & input data)
ethereumethereum
Blocks:
Includes parent block's hash
Series of transactions
Includes cryptographic proof-of-work
Author takes a reward
ethereumethereum
Block-tree forms from blocks
“GHOST” protocol:
Reduced to block-chain as the root-leaf that required greatest computation (sum of
proof-of-work, including immediate relatives)
ethereumethereum
Useful abstraction platform for:
Virtual currencies (Bitcoin)
Digital proxy currencies (CFD, 'Goldcoin')
Financial instruments (Cons. Tape, Mastercoin)
Registrars (ICANN, Namecoin)
ethereumethereum
Limitations
Scalability all nodes evaluate all transactions, store all state
Public impossible to work with secrets