S.C. Code Ann. § 11-41-120: Executive signature and State seal requirements.

All bonds issued under this chapter must be signed by the Governor and the State Treasurer and attested by the Secretary of State. The Governor, State Treasurer, and Secretary of State may sign these obligations by a facsimile of their signatures. The Great Seal of the State must be affixed to, impressed on, or reproduced upon each of them. The delivery of the bonds executed and authenticated, as provided in the resolution, is valid notwithstanding changes in officers or seal occurring after the execution or authentication.