The importance and magnitude of the problem facing society about preserving our digitally encoded intellectual and cultural capital is not in doubt. However, there are a number of fundamental challenges which must be overcome in order to provide adequate solutions. This paper will describe the progress which has been made so far in solving these challenges and the further progress which must be made if we are to safeguard our digital holdings. For example, the terminology used in different disciplines is a barrier to sharing ideas and improving practice; the OAIS reference model has provided a partial solution to this but more can be done. There is a fundamental divide in mind-sets and approaches between those dealing with rendered objects and those dealing with digital objects which are processed rather than rendered which causes much confusion; this paper will provide a view which resolves these differences. Claims for the various digital preservation techniques abound, yet which ones actually work? A fundamental approach to providing rather convincing evidence, which should be used to test any such claims, will be described. Claims that a repository is preserving the digital holdings with which it has been entrusted are hard to test; how can depositors in or funders of repositories know which repositories can be trusted? This talk will describe the mechanism which is being developed to ISO certify repositories and what is left to do.