Transitions
Components of a Transition
An Aleo transition is serialized in the following format:
| Parameter | Type | Description |
|---|---|---|
id | finite field element | The transition id, which is computed via the Merkle tree digest formed from the Input and Output IDs |
program_id | string | The program ID, which is associated with a verification key on a globally maintained map on the ledger. |
function_name | string | The function name, which is used to compute a function_id using the program_id. |
inputs | array of Inputs | The transition Inputs, which can be a constant, public, private, or inputRecord |
outputs | array of Outputs | The transition Outputs, which can be a constant, public, private, or outputRecord |
finalize | array | The inputs for finalize |
tpk | group element | The transition public key, which is used to verify the digital signature provided by the owner in a transaction |
tcm | finite field element | The transition commitment |
Input Record
An inputRecord is a tuple consisting of a serial_number and a tag. Recall that since the serial number is disclosed on the ledger, this publicly announces the record which is being spent.
Recall that serial numbers are posted onto the ledger to announce that previously unspent records have now been spent. Each record has an associated tag which is used to keep track of records which are spendable by the user. A tag is computed via tag = CRH.Eval(sk_tag, record_commitment).
Output Record
An outputRecord consists of a record_commitment, checksum, and a record_ciphertext. A record_commitment is computed via Pedersen.Commit(pp, apk || data || nonce ; r). The record_encryption is computed via SymmEnc.Eval(pp, apk || data || nonce ; r) and the checksum, used to verify the integrity of the record commitment, is computed via record_commitment = CRH.Eval(record_encryption).