Does section 360.5 of the California Penal Code require an authorization letter to be signed by an authorized agent?

Section 360, however, like section 360.5, relates to the statute of limitations. In relevant part it provides: "No acknowledgment or promise is sufficient evidence of a new or continuing contract, by which to take the case out of the operation of this title, unless the same is contained in some writing, signed by the party to be charged thereby, ..." Section 360 sets forth the kind of evidence needed to prove the existence of a promise or acknowledgment of a new or continuing contract which tolls the statute of limitations (Easton v. Ash (1941) 18 Cal.2d 530, 536, 116 P.2d 433), while section 360.5 sets forth the kind of evidence needed to prove the existence of a waiver of the statute of limitations. Neither section 360.5 nor section 360 expressly provides for a writing signed by an authorized agent.