This certificate mentions file identifiers computed from sha256 hashes that cannot under the current state of technology be counterfeited. No distinct files can share the same identifier.
This certificate displays at the top its own b58 encoded identifier computed from an sha224 hash: XXXthe id hereXXX. These settings produce a 39 character string that fits within the current 40 byte Bitcoin blockchain limit. Again, under the current state of the technology, it is not possible to counterfeit this identifier by producing another certificate file with the same id.
The certificate id XXX---XXX has been registered as OP_RETURN data on the Bitcoin transaction XXX---XXX that can be verified here, here, here. (links) This certificate file hence produces a proof chain from the Bitcoin blockchain ledger to your file, that offers you a proof that at the transaction date you had knowledge of the identifier of your file, which you may or not have decided to keep private or share publicly. By using KeeeX you had a chance to sign your original file.
Although KeeeX will make its best efforts to keep this certificate accessible and indexable by search engines, we cannot guarantee this. If some file id is of interest to you it is thus your responsability and interest to download it and make sure to preserve it indefinitely. Once downloaded, you may verify its integrity using the KeeeX app.
You may wonder why we chose to mutualise this certificate for potentially a large number of files. The reason is that a single certificate may provide a proof of existence for an unlimited number of files and no blockchain, BItcoin inclusive, is designed to satisfy the massive notarisation needs, since both the block size and rate are constrained.