# privateKey The private key blob, or `nil` when `DiscardPK` was set. ``` let privateKey: String? ``` ## Discussion Extracted from the `PrivateKey=` line when present (never returned by Tor when `DiscardPK` was included in the request). Format is `:` verbatim — round- tripping through [`OnionKeySpec.providedV3(_:)`](/documentation/Tor/OnionKeySpec/providedV3(_:)) requires passing only the `` suffix. - Stability: immutable. > Important: Secret material. Treat as a credential.