Substitute Deserialize* nodes with deserialized subtrees We can estimate cost of the tree evaluation only after this step.
Verifier Step 4: For every leaf node, compute the commitment a from the challenge e and response $z$, per the verifier algorithm of the leaf's Sigma-protocol.
Verifier Step 4: For every leaf node, compute the commitment a from the challenge e and response $z$, per the verifier algorithm of the leaf's Sigma-protocol. If the verifier algorithm of the Sigma-protocol for any of the leaves rejects, then reject the entire proof.
Deserializes given script bytes using ValueSerializer (i.e.
Deserializes given script bytes using ValueSerializer (i.e. assuming expression tree format).
It also measures tree complexity adding to the total estimated cost of script execution.
The new returned context contains increased initCost
and should be used for further processing.
The method SHOULD be called only inside trySoftForkable scope, to make deserialization soft-forkable.
NOTE: While ErgoTree is always of type SigmaProp, ValueSerializer can serialize expression of any type. So it cannot be replaced with ErgoTreeSerializer here.
Full reduction of initial expression given in the ErgoTree form to a SigmaBoolean value (which encodes whether a sigma-protocol proposition or a boolean value, so true or false).
Full reduction of initial expression given in the ErgoTree form to a SigmaBoolean value (which encodes whether a sigma-protocol proposition or a boolean value, so true or false).
Works as follows: 1) parse ErgoTree instance into a typed AST 2) go bottom-up the tree to replace DeserializeContext nodes only 3) estimate cost and reduce the AST to a SigmaBoolean instance (so sigma-tree or trivial boolean value)
- input ErgoTree expression to reduce
- context used in reduction
- script environment
sigma boolean and the updated cost counter after reduction
Extracts proposition for ErgoTree handing soft-fork condition.
Extracts proposition for ErgoTree handing soft-fork condition.
soft-fork handler
This method is used in both prover and verifier to compute SigmaBoolean value.
This method is used in both prover and verifier to compute SigmaBoolean value.
As the first step the cost of computing the exp
expression in the given context is estimated.
If cost is above limit
then exception is returned and exp
is not executed
else exp
is computed in the given context and the resulting SigmaBoolean returned.
the context in which exp
should be executed
environment of system variables used by the interpreter internally
expression to be executed in the given context
result of script reduction
ReductionResult
call back to setup new context (with updated cost limit) to be passed next time
Executes the script in a given context.
Executes the script in a given context.
Step 1: Deserialize context variables
Step 2: Evaluate expression and produce SigmaProp value, which is zero-knowledge statement (see also SigmaBoolean
).
Step 3: Verify that the proof is presented to satisfy SigmaProp conditions.
environment of system variables used by the interpreter internally
ErgoTree expression to execute in the given context and verify its result
the context in which exp
should be executed
The proof of knowledge of the secrets which is expected by the resulting SigmaProp
message bytes, which are used in verification of the proof
verification result or Exception.
If if the estimated cost of execution of the exp
exceeds the limit (given in context
),
then exception if thrown and packed in Try.
If left component is false, then:
1) script executed to false or
2) the given proof failed to validate resulting SigmaProp conditions.
reduceToCrypto