Instance Method

multiply(_:)

Creates a new P256K.Signing.PrivateKey by computing secret_key' = (secret_key × tweak) mod n via secp256k1_ec_seckey_tweak_mul, where n is the secp256k1 curve order.

iOS 13.0+
macCatalyst 13.0+
macOS 10.15+
tvOS 13.0+
visionOS 1.0+
watchOS 6.0+

func multiply(_ tweak: [UInt8]) throws -> P256K.Signing.PrivateKey

Parameters

tweak: A 32-byte tweak scalar; must be non-zero and less than n.

Return Value

A new P256K.Signing.PrivateKey with the scaled secret scalar.

Discussion

Scalar multiplication pairs with public-key point scaling through G × (sk × t) = pk × t. Less common than add(_:) in Bitcoin workflows but useful for blinding schemes and some threshold-signature constructions.

Throws

secp256k1Error.underlyingCryptoError if the tweak is invalid or the result fails secp256k1_ec_seckey_verify.