So the use-case is a to a very tentative optimization. This tentative optimization is achieved by introducing a very complicated algorithm that is not guarantee

So the use-case is a to a very tentative optimization. This tentative optimization is achieved by introducing a very complicated algorithm that is not guaranteed to run in finite time. You could also check signatures when loading the data and keep the original bytearray separately in slow/cheap storage. That way you can sign RDF graphs like you sign any bytearray and keep a simple design.