California Code, Civil Code - CIV § 9364

(a) A public entity may, in its discretion, permit the direct contractor to give the public entity a release bond.  The bond shall be executed by an admitted surety insurer, in an amount equal to 125 percent of the claim stated in the stop payment notice, conditioned for the payment of any amount the claimant recovers in an action on the claim, together with court costs if the claimant prevails.

(b) On receipt of a release bond, the public entity shall not withhold funds from the direct contractor pursuant to the stop payment notice.

(c) The surety on a release bond is jointly and severally liable to the claimant with the sureties on any payment bond given under Chapter 5 (commencing with Section 9550).