Skip to content

Latest commit

 

History

History
 
 

crypto

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
ts
ts
 
 
.npmignore
.npmignore
 
 
CHANGELOG.md
CHANGELOG.md
 
 
README.md
README.md
 
 
jest.config.js
jest.config.js
 
 
package-lock.json
package-lock.json
 
 
package.json
package.json
 
 
tsconfig.json
tsconfig.json
 
 

README.md

maci-crypto

NPM Package Actions Status

This module implements abstractions over cryptographic functions which MACI employs.

Constants

NOTHING_UP_MY_SLEEVE: The Keccak256 hash of the string "Maci", modulo the BN254 group order.

Types and interfaces

PrivKey: A private key (a random value modulo the BN254 group order).

PubKey: An EdDSA public key.

Keypair: A private key and the public key it generates.

EcdhSharedKey: An Elliptic-curve Diffie–Hellman shared key.

Plaintext: An array of unencrypted values.

Ciphertext: Encrypted Plaintext. This data structure abstracts over the initialisation vector and encrypted data.

Signature: A signature. This data structure abstracts over theR8 and S values.

Classes

G1Point: A point in the group G_1 as defined in EIP-197.

G2Point: A point in the group G_2 as defined in EIP-197.

Functions

genRandomBabyJubValue: Returns a cryptographically secure random value modulo the BN254 group order, and prevents modulo bias. Relies on Node.js's crypto.randomBytes(32) for entropy.

genRandomSalt: BigInt

Returns a secure random salt value. Wraps genRandomBabyJubValue().

genPrivKey: PrivKey

Returns a secure random private key. Wraps genRandomBabyJubValue().

genPubKey = (privKey: PrivKey): PubKey

Generates the public key associated with the given private key.

genKeypair: Generates a random private key and its associated public key.

formatPrivKeyForBabyJub = (privKey: PrivKey): Formats a random private key to be compatible with the BabyJub curve. This is the format which should be passed into the PubKey and other circuits.

packPubKey = (pubKey: PubKey): Buffer: Losslessly reduces the size of the representation of a public key.

unpackPubKey = (packed: Buffer): PubKey: Restores the original PubKey from its packed representation.

genEcdhSharedKey = (privKey: PrivKey, pubKey: PubKey): EcdhSharedKey

Generates an ECDH shared key.

encrypt = (plaintext: Plaintext, sharedKey: EcdhSharedKey): Ciphertext

Encrypts the plaintext with the given key and returns the associated ciphertext.

decrypt = (ciphertext: Ciphertext, sharedKey: EcdhSharedKey): Plaintext

Decrypts the ciphertext using the given key.

sign = (privKey: PrivKey, message: Plaintext): Signature

Produces a signature of the given message using the private key.

verifySignature = (message: Plaintext, signature: Signature, publicKey: PubKey): boolean

Checks whether the given signature is valid.

Hash functions

sha256Hash = (input: BigInt[]): BigInt: a wrapper function over ethers.utils.soliditySha256, where the output is modulo the BN254 group order.

hashOne = (elements: Plaintext): BigInt: the Poseidon hash function for one input. Equivalent to hash2([input, 0]).

hash2 = (elements: Plaintext): BigInt: the Poseidon hash function for 2 inputs.

hashLeftRight = (left: BigInt, right: BigInt): BigInt: equivalent to hash2([left, right]).

hash3 = (elements: Plaintext): BigInt: the Poseidon hash function for 3 inputs.

hash4 = (elements: Plaintext): BigInt: the Poseidon hash function for 4 inputs.

hash5 = (elements: Plaintext): BigInt: the Poseidon hash function for 5 inputs.

hash12 = (elements: Plaintext): BigInt: the Poseidon hash function for 12 inputs. Combines other Poseidon hash functions (accepting 5 and 6 inputs) to do so. Given the following inputs [i_0, i_1, ... i_11], this function hashes them in the following manner:

hash4(
    hash5([i_0, i_1, i_2, i_3, i_4]),
    hash5([i_5, i_6, i_7, i_8, i_9]),
    i_10,
    i_11,
)