Aleo

Aleo is a blockchain platform built around privacy-preserving smart contracts. Unlike traditional blockchains where transaction data is publicly visible, Aleo uses zero-knowledge proofs (zk-SNARKs) to let users prove the correctness of a transaction — such as a token transfer or a contract execution — without revealing the underlying inputs.

Every Aleo transaction is accompanied by one of these proofs. Because generating a proof is a complex operation, Aleo is designed to allow delegation: a user can authorize a transaction and hand off the heavy proof-generation work to a third-party prover, without giving that prover access to their private key.

This delegation is what shapes the signing interface described below. Signing an Aleo transaction is not just a matter of producing a signature over a message — the signer must also compute certain values (such as input identifiers and a transition view key) that are needed by the prover to construct a valid proof.

Signing Interface

Two signing methods are supported: account signatures and delegated signing. Both accept a JSON request body and return a JSON response.

For full cryptographic detail, refer to the Aleo signature specification.

Input format

Both signing methods share the same top-level input structure:

Field	Type	Required	Description
`inputs`	array	Yes	One or more inputs to sign (see below)
`functionId`	string	Delegated only	Field element identifying the function being called
`isRoot`	boolean	Delegated only	Whether this is a root-level call
`checksum`	string	Delegated only(*)	Integrity checksum of the function. Omitted for older programs.

(*) Present only for programs that include a checksum.

Input types

Each entry in inputs has a type field and a data array of field elements (as decimal strings).

Type	Used in	Description
`account`	Account sig	Arbitrary message fields for account-level signing
`public`	Delegated	Publicly visible function input
`private`	Delegated	Encrypted function input
`record`	Delegated	A record commitment being consumed
`externalRecord`	Delegated	A record from an external program
`dynamicRecord`	Delegated	A dynamically referenced record

Examples

Account signature request

JSON

{
  "inputs": [
    {
      "type": "account",
      "data": [
        "6716502009016430053183507170699594817265084671791777241413633239014382669047",
        "1099471864310681484047468615352474858081227942590554598086745066318936376057"
      ]
    }
  ]
}

Delegated signing request

JSON

{
  "functionId": "7997765759116436245054600309458180601753471573319679234621276897246672782660",
  "isRoot": true,
  "checksum": "1503530553220993152536984095177360228202084361422343390783285383306871595686",
  "inputs": [
    {
      "type": "record",
      "data": [
        "3620054965614225011843835598412969685728959723873203421423497665637723824061",
        "4723421622337407625451130429846704556698341853293634966801114008038334673712"
      ]
    },
    {
      "type": "private",
      "data": [
        "2854583002587711767714127780974314920905498857787333885876654043294119228416",
        "166688728"
      ]
    },
    {
      "type": "private",
      "data": [
        "1237940039285380281610076208"
      ]
    }
  ]
}

Output format

All field element values are returned as decimal strings.

Field	Type	Present in	Description
`signature`	string	Both	Bech32m-encoded Schnorr signature (`sign1…`)
`tvk`	string	Delegated only	Transition view key (field element)
`tcm`	string	Delegated only	Transition commitment (field element)
`gammas`	array of strings	Delegated only	One gamma value per `record`-type input, in order

Account signature response

JSON

{
  "signature": "sign1g03t2q98yh7kets29s05en3ljp90umlhf5kwzhecsaalcxpffvqmnafyspdnmu42qjgj905f964yxl2ph7mz70dqy503xxyjj4rwxqur22qjwn4zc0pzv87twjygsz9m7ekljmuw4jpzf68rwuq99r0tp735vs6220q7tp60nr7llkwstcvu49wdhydx5x2s3sftjskzawhqvh8arjf"
}

Delegated signing response

JSON

{
  "signature": "sign1g03t2q98yh7kets29s05en3ljp90umlhf5kwzhecsaalcxpffvqmnafyspdnmu42qjgj905f964yxl2ph7mz70dqy503xxyjj4rwxqur22qjwn4zc0pzv87twjygsz9m7ekljmuw4jpzf68rwuq99r0tp735vs6220q7tp60nr7llkwstcvu49wdhydx5x2s3sftjskzawhqvh8arjf",
  "tvk": "6839744283125714768219049408772295603189719087890464618622056790088127041542",
  "tcm": "36661113237169170635146585844811003819221318715282919854177900780199067452",
  "gammas": [
    "4875506682083978504504607329729976086652196269888800393640799801065716748965"
  ]
}