Crypto Module

Table of contents

Classes

• AccQueue
• G1Point
• G2Point
• IncrementalQuinTree

Interfaces

• Keypair
• PoseidonFuncs
• Queue
• Signature

Type Aliases

• Ciphertext
• EcdhSharedKey
• Leaf
• PathElements
• Plaintext
• Point
• PrivKey
• PubKey

Variables

• NOTHING_UP_MY_SLEEVE
• SNARK_FIELD_SIZE

Functions

• bigInt2Buffer
• calcDepthFromNumLeaves
• deepCopyBigIntArray
• formatPrivKeyForBabyJub
• genEcdhSharedKey
• genKeypair
• genPrivKey
• genPubKey
• genRandomBabyJubValue
• genRandomSalt
• genTreeCommitment
• genTreeProof
• hash12
• hash2
• hash3
• hash4
• hash5
• hashLeftRight
• hashN
• hashOne
• inCurve
• packPubKey
• poseidonDecrypt
• poseidonDecryptWithoutCheck
• poseidonEncrypt
• sha256Hash
• sign
• stringifyBigInts
• unpackPubKey
• unstringifyBigInts
• verifySignature

Type Aliases

Ciphertext

Ƭ Ciphertext<N>: N[]

Type parameters

Name	Type
N	bigint

Defined in

crypto/ts/types.ts:21

---

EcdhSharedKey

Ƭ EcdhSharedKey<N>: [N, N]

Type parameters

Name	Type
N	bigint

Defined in

crypto/ts/types.ts:12

---

Leaf

Ƭ Leaf: bigint

Defined in

crypto/ts/types.ts:64

---

PathElements

Ƭ PathElements: bigint[][]

Defined in

crypto/ts/types.ts:24

---

Plaintext

Ƭ Plaintext<N>: N[]

Type parameters

Name	Type
N	bigint

Defined in

crypto/ts/types.ts:18

---

Point

Ƭ Point<N>: [N, N]

Type parameters

Name	Type
N	SnarkBigNumber

Defined in

crypto/ts/types.ts:15

---

PrivKey

Ƭ PrivKey: SnarkBigNumber

Defined in

crypto/ts/types.ts:6

---

PubKey

Ƭ PubKey<N>: [N, N]

Type parameters

Name	Type
N	bigint

Defined in

crypto/ts/types.ts:9

Variables

NOTHING_UP_MY_SLEEVE

• Const NOTHING_UP_MY_SLEEVE: bigint

Defined in

crypto/ts/constants.ts:10

---

SNARK_FIELD_SIZE

• Const SNARK_FIELD_SIZE: bigint = r

Defined in

crypto/ts/constants.ts:6

Functions

bigInt2Buffer

▸ bigInt2Buffer(i): Buffer

Convert a BigInt to a Buffer

Parameters

Name	Type	Description
i	bigint	the bigint to convert

Returns

Buffer

the buffer

Defined in

crypto/ts/bigIntUtils.ts:127

---

calcDepthFromNumLeaves

▸ calcDepthFromNumLeaves(hashLength, numLeaves): number

Calculate the depth of a tree given the number of leaves

Parameters

Name	Type	Description
hashLength	number	the hashing function param length
numLeaves	number	how many leaves

Returns

number

the depth

Defined in

crypto/ts/utils.ts:10

---

deepCopyBigIntArray

▸ deepCopyBigIntArray(arr): bigint[]

Create a copy of a bigint array

Parameters

Name	Type	Description
arr	bigint[]	the array of bigints to copy

Returns

bigint[]

a deep copy of the array

Defined in

crypto/ts/bigIntUtils.ts:110

---

formatPrivKeyForBabyJub

▸ formatPrivKeyForBabyJub(privKey): bigint

An internal function which 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.

Parameters

Name	Type	Description
privKey	SnarkBigNumber	A private key generated using genPrivKey()

Returns

bigint

A BabyJub-compatible private key.

Defined in

crypto/ts/keys.ts:28

---

genEcdhSharedKey

▸ genEcdhSharedKey(privKey, pubKey): EcdhSharedKey

Generates an Elliptic-Curve Diffie–Hellman (ECDH) shared key given a private key and a public key.

Parameters

Name	Type	Description
privKey	SnarkBigNumber	A private key generated using genPrivKey()
pubKey	PubKey	A public key generated using genPubKey()

Returns

EcdhSharedKey

The ECDH shared key.

Defined in

crypto/ts/keys.ts:76

---

genKeypair

▸ genKeypair(): Keypair

Generates a keypair.

Returns

Keypair

a keypair

Defined in

crypto/ts/keys.ts:60

---

genPrivKey

▸ genPrivKey(): bigint

Generate a private key

Returns

bigint

A random seed for a private key.

Defined in

crypto/ts/keys.ts:13

---

genPubKey

▸ genPubKey(privKey): PubKey

Parameters

Name	Type	Description
privKey	SnarkBigNumber	A private key generated using genPrivKey()

Returns

PubKey

A public key associated with the private key

Defined in

crypto/ts/keys.ts:51

---

genRandomBabyJubValue

▸ genRandomBabyJubValue(): bigint

Returns a BabyJub-compatible random value. We create it by first generating a random value (initially 256 bits large) modulo the snark field size as described in EIP197. This results in a key size of roughly 253 bits and no more than 254 bits. To prevent modulo bias, we then use this efficient algorithm: http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/lib/libc/crypt/arc4random_uniform.c

Returns

bigint

A BabyJub-compatible random value.

Defined in

crypto/ts/babyjub.ts:115

---

genRandomSalt

▸ genRandomSalt(): bigint

Generate a random value

Returns

bigint

A BabyJub-compatible salt.

Defined in

crypto/ts/keys.ts:19

---

genTreeCommitment

▸ genTreeCommitment(leaves, salt, depth): bigint

A helper function which hashes a list of results with a salt and returns the hash.

Parameters

Name	Type	Description
leaves	bigint[]	A list of values
salt	bigint	A random salt
depth	number	The tree depth

Returns

bigint

The hash of the leaves and the salt, with the salt last

Defined in

crypto/ts/utils.ts:30

---

genTreeProof

▸ genTreeProof(index, leaves, depth): bigint[][]

A helper function to generate the tree proof for the value at the given index in the leaves

Parameters

Name	Type	Description
index	number	The index of the value to generate the proof for
leaves	bigint[]	A list of values
depth	number	The tree depth

Returns

bigint[][]

The proof

Defined in

crypto/ts/utils.ts:47

---

hash12

▸ hash12(elements): bigint

A convenience function to use Poseidon to hash a Plaintext with no more than 13 elements

Parameters

Name	Type	Description
elements	Plaintext	The elements to hash

Returns

bigint

The hash of the elements

Defined in

crypto/ts/hashing.ts:130

---

hash2

▸ hash2(elements): bigint

Parameters

Name	Type
elements	Plaintext

Returns

bigint

Defined in

crypto/ts/hashing.ts:119

---

hash3

▸ hash3(elements): bigint

Parameters

Name	Type
elements	Plaintext

Returns

bigint

Defined in

crypto/ts/hashing.ts:120

---

hash4

▸ hash4(elements): bigint

Parameters

Name	Type
elements	Plaintext

Returns

bigint

Defined in

crypto/ts/hashing.ts:121

---

hash5

▸ hash5(elements): bigint

Parameters

Name	Type
elements	Plaintext

Returns

bigint

Defined in

crypto/ts/hashing.ts:122

---

hashLeftRight

▸ hashLeftRight(left, right): bigint

Hash two BigInts with the Poseidon hash function

Parameters

Name	Type	Description
left	bigint	The left-hand element to hash
right	bigint	The right-hand element to hash

Returns

bigint

The hash of the two elements

Defined in

crypto/ts/hashing.ts:85

---

hashN

▸ hashN(numElements, elements): bigint

Hash up to N elements

Parameters

Name	Type	Description
numElements	number	The number of elements to hash
elements	Plaintext	The elements to hash

Returns

bigint

The hash of the elements

Defined in

crypto/ts/hashing.ts:101

---

hashOne

▸ hashOne(preImage): bigint

Hash a single BigInt with the Poseidon hash function

Parameters

Name	Type	Description
preImage	bigint	The element to hash

Returns

bigint

The hash of the element

Defined in

crypto/ts/hashing.ts:159

---

inCurve

▸ inCurve(p): boolean

Determines if a given point lies on the Baby Jubjub elliptic curve by verifying the curve equation. This function checks if the point satisfies the curve equation ax^2 + y^2 = 1 + dx^2y^2.

Parameters

Name	Type	Description
p	Point	The point to check, represented as a pair of bigint values.

Returns

boolean

True if the point is on the curve, otherwise false.

Defined in

node_modules/.pnpm/@zk-kit+baby-jubjub@1.0.1/node_modules/@zk-kit/baby-jubjub/dist/types/baby-jubjub.d.ts:38

---

packPubKey

▸ packPubKey(pubKey): bigint

Losslessly reduces the size of the representation of a public key

Parameters

Name	Type	Description
pubKey	PubKey	The public key to pack

Returns

bigint

A packed public key

Defined in

crypto/ts/keys.ts:35

---

poseidonDecrypt

▸ poseidonDecrypt(ciphertext, key, nonce, length): PlainText<bigint>

Decrypt some ciphertext using poseidon encryption

Parameters

Name	Type	Description
ciphertext	CipherText<bigint>	the ciphertext to decrypt
key	EncryptionKey<bigint>	the key to decrypt with
nonce	bigint	the nonce used to encrypt
length	number	the length of the plaintext

Returns

PlainText<bigint>

the plaintext

Defined in

node_modules/.pnpm/@zk-kit+poseidon-cipher@0.3.1/node_modules/@zk-kit/poseidon-cipher/dist/types/poseidonCipher.d.ts:18

---

poseidonDecryptWithoutCheck

▸ poseidonDecryptWithoutCheck(ciphertext, key, nonce, length): PlainText<bigint>

Decrypt some ciphertext using poseidon encryption

Parameters

Name	Type	Description
ciphertext	CipherText<bigint>	the ciphertext to decrypt
key	EncryptionKey<bigint>	the key to decrypt with
nonce	bigint	the nonce used to encrypt
length	number	the length of the plaintext

Returns

PlainText<bigint>

the plaintext

Dev

Do not throw if the plaintext is invalid

Defined in

node_modules/.pnpm/@zk-kit+poseidon-cipher@0.3.1/node_modules/@zk-kit/poseidon-cipher/dist/types/poseidonCipher.d.ts:28

---

poseidonEncrypt

▸ poseidonEncrypt(msg, key, nonce): CipherText<bigint>

Encrypt some plaintext using poseidon encryption

Parameters

Name	Type	Description
msg	PlainText<bigint>	the message to encrypt
key	EncryptionKey<bigint>	the key to encrypt with
nonce	bigint	the nonce to avoid replay attacks

Returns

CipherText<bigint>

the ciphertext

Defined in

node_modules/.pnpm/@zk-kit+poseidon-cipher@0.3.1/node_modules/@zk-kit/poseidon-cipher/dist/types/poseidonCipher.d.ts:9

---

sha256Hash

▸ sha256Hash(input): bigint

Hash an array of uint256 values the same way that the EVM does.

Parameters

Name	Type	Description
input	bigint[]	the array of values to hash

Returns

bigint

a EVM compatible sha256 hash

Defined in

crypto/ts/hashing.ts:15

---

sign

▸ sign(privateKey, message): Signature<bigint>

Signs a message using the provided private key, employing Poseidon hashing and EdDSA with the Baby Jubjub elliptic curve.

The private key must be an instance of Buffer, Uint8Array or a string. The input will be used to generate entropy and there is no limit in size. The string is used as a set of raw bytes (in UTF-8) and is typically used to pass passwords or secret messages. If you want to pass a bigint, a number or a hexadecimal, be sure to convert them to one of the supported types first. The 'conversions' module in @zk-kit/utils provides a set of functions that may be useful in case you need to convert types.

Parameters

Name	Type	Description
privateKey	string | Uint8Array | Buffer	The private key used to sign the message.
message	BigNumberish	The message to be signed.

Returns

Signature<bigint>

The signature object, containing properties relevant to EdDSA signatures, such as 'R8' and 'S' values.

Defined in

node_modules/.pnpm/@zk-kit+eddsa-poseidon@1.0.2/node_modules/@zk-kit/eddsa-poseidon/dist/types/eddsa-poseidon.d.ts:57

---

stringifyBigInts

▸ stringifyBigInts(input): StringifiedBigInts

Given an input of bigint values, convert them to their string representations

Parameters

Name	Type	Description
input	BigIntVariants	The input to convert

Returns

StringifiedBigInts

The input with bigint values converted to string

Defined in

crypto/ts/bigIntUtils.ts:78

---

unpackPubKey

▸ unpackPubKey(packed): PubKey

Restores the original PubKey from its packed representation

Parameters

Name	Type	Description
packed	bigint	The value to unpack

Returns

PubKey

The unpacked public key

Defined in

crypto/ts/keys.ts:42

---

unstringifyBigInts

▸ unstringifyBigInts(input): BigIntVariants

Given an input containing string values, convert them to bigint

Parameters

Name	Type	Description
input	StringifiedBigInts	The input to convert

Returns

BigIntVariants

the input with string values converted to bigint

Defined in

crypto/ts/bigIntUtils.ts:9

---

verifySignature

▸ verifySignature(message, signature, publicKey): boolean

Verifies an EdDSA signature using the Baby Jubjub elliptic curve and Poseidon hash function.

Parameters

Name	Type	Description
message	BigNumberish	The original message that was be signed.
signature	Signature	The EdDSA signature to be verified.
publicKey	Point	The public key associated with the private key used to sign the message.

Returns

boolean

Returns true if the signature is valid and corresponds to the message and public key, false otherwise.

Defined in

node_modules/.pnpm/@zk-kit+eddsa-poseidon@1.0.2/node_modules/@zk-kit/eddsa-poseidon/dist/types/eddsa-poseidon.d.ts:65