The area of synthetic genomics has seen rapid progress in recent years. DNA molecules are increasingly being synthesized in the laboratory. New biological organisms that do not exist in the natural world are being created using synthesized DNA. A major concern in this domain is that a malicious actor can potentially tweak with a benevolent synthesized DNA molecule and create a harmful organism [1] or create a DNA molecule with malicious properties. To detect if a synthesized DNA molecule has been modified from the original version created in the laboratory, the authors in [13] had proposed a digital signature protocol for creating a signed DNA molecule. It uses an identity-based signatures and error correction codes to sign a DNA molecule and then physically embed the digital signature in the molecule itself. However there are several challenges that arise in more complex molecules because of various forms of DNA mutations as well as size restrictions of the molecule itself that determine its properties, the earlier work is limited in scope. In this work, we extend the work in several directions to address these problems.