Optical coherence tomography (OCT) imaging systems for imaging uniquely identifiable structure are provided including a source having an associated source arm path and having an associated reference arm path coupled to the source path, the reference arm path having an associated reference arm path length. A sample having an associated sample arm path coupled to the source arm and reference arm paths is provided. Processing methods to convert the depth-dependent image data to a uniquely identifiable code are provided. Related methods and computer program products are also provided.