crypto

func AddG1 ¶

func AddG1(a, b types.G1Point) (*types.G1Point, error)

AddG1 adds two G1 points This allows any point as long as it's on the curve and in the subgroup.

func AddG2 ¶

func AddG2(a, b types.G2Point) (*types.G2Point, error)

AddG2 adds two G2 points

func ComputeAppPublicKeyFromMaster ¶

func ComputeAppPublicKeyFromMaster(appID string, masterPublicKey types.G2Point) (*types.G1Point, error)

ComputeAppPublicKeyFromMaster computes the application's public encryption key using the master public key and pairing operations

func ComputeLagrangeCoefficient ¶

func ComputeLagrangeCoefficient(i int64, participants []int64) *fr.Element

ComputeLagrangeCoefficient computes the Lagrange coefficient for participant i

func ComputeMasterPublicKey ¶

func ComputeMasterPublicKey(allCommitments [][]types.G2Point) (*types.G2Point, error)

ComputeMasterPublicKey computes the master public key from commitments

func DecryptForApp ¶

func DecryptForApp(appID string, appPrivateKey types.G1Point, ciphertext []byte) ([]byte, error)

DecryptForApp decrypts data using the recovered application private key with AES-GCM

This implements the Boneh-Franklin IBE decryption:

• Validates ciphertext format (magic, version)
• Extracts C1 from ciphertext
• Computes g_ID = e(appPrivateKey, C1) using pairing
• Since appPrivateKey = [s]Q_ID and C1 = [r]P: g_ID = e([s]Q_ID, [r]P) = e(Q_ID, P)^(r*s) = e(Q_ID, masterPublicKey)^r
• This matches the encryption key, allowing successful decryption
• Derives AES key from g_ID using HKDF with version-aware domain separation
• Decrypts with AES-GCM and verifies authentication using AAD

Expected ciphertext format matches EncryptForApp output

func EncryptForApp ¶

func EncryptForApp(appID string, masterPublicKey types.G2Point, plaintext []byte) ([]byte, error)

EncryptForApp encrypts data for an application using full IBE with AES-GCM

This implements the Boneh-Franklin IBE scheme: - Computes Q_ID = H_1(app_id) ∈ G1 - Chooses random r ∈ Fr - Computes C1 = r*P where P is G2 generator - Computes g_ID = e(Q_ID, masterPublicKey)^r using pairing - Derives AES key from g_ID using HKDF with version-aware domain separation - Uses AES-GCM for authenticated encryption with AAD (appID || version || C1)

Ciphertext format (version 1):

[0:3]     magic ("IBE")
[3:4]     version (0x01)
[4:100]   C1 (compressed G2 point, 96 bytes)
[100:112] nonce (12 bytes)
[112:]    encrypted data + GCM tag

func EvaluatePolynomial ¶

func EvaluatePolynomial(poly polynomial.Polynomial, x int64) *fr.Element

EvaluatePolynomial evaluates a polynomial at point x

func GetAppPublicKey ¶

func GetAppPublicKey(appID string) (*types.G1Point, error)

GetAppPublicKey computes the public key for an application given the master public key This implements Q_ID = H_1(app_id) for IBE encryption

func HashAcknowledgementForMerkle ¶

func HashAcknowledgementForMerkle(ack *types.Acknowledgement) [32]byte

HashAcknowledgementForMerkle creates a keccak256 hash of an acknowledgement for merkle leaf (Phase 3) The hash format matches the Solidity implementation for cross-validation keccak256(abi.encodePacked(playerID, dealerID, epoch, shareHash, commitmentHash))

func HashCommitment ¶

func HashCommitment(commitments []types.G2Point) [32]byte

HashCommitment hashes commitments

func HashShareForAck ¶

func HashShareForAck(share *fr.Element) [32]byte

HashShareForAck creates a keccak256 hash of a share for use in acknowledgements (Phase 3) This commits the player to the specific share they received

func HashToG1 ¶

func HashToG1(appID string) (*types.G1Point, error)

HashToG1 hashes a string to a G1 point using proper hash-to-curve

func PointsEqualG2 ¶

func PointsEqualG2(a, b types.G2Point) (bool, error)

PointsEqualG2 checks if two G2 points are equal

func RecoverAppPrivateKey ¶

func RecoverAppPrivateKey(appID string, partialSigs map[int64]types.G1Point, threshold int) (*types.G1Point, error)

RecoverAppPrivateKey recovers app private key from partial signatures. Returns an error if fewer than threshold signatures are provided.

func RecoverSecret ¶

func RecoverSecret(shares map[int64]*fr.Element) (*fr.Element, error)

RecoverSecret recovers secret from shares using Lagrange interpolation

func ScalarMulG1 ¶

func ScalarMulG1(point types.G1Point, scalar *fr.Element) (*types.G1Point, error)

ScalarMulG1 performs scalar multiplication on G1

func ScalarMulG2 ¶

func ScalarMulG2(point types.G2Point, scalar *fr.Element) (*types.G2Point, error)

ScalarMulG2 performs scalar multiplication on G2

func VerifyShareWithCommitments ¶

func VerifyShareWithCommitments(nodeID int, share *fr.Element, commitments []types.G2Point) bool

VerifyShareWithCommitments verifies a share against polynomial commitments