Blockchain development required

We are looking for blockchain developer for multiple projects. For now requirement is to upload documents and encrypt them and produce Hash from the blockchain. In addition, we can refer back to that Hash to get all info of the uploaded person, by name, date and all details. What i need: 1. I need the Hash produced, to be printed with water printing (to get difficult to be edited) into the certificate.. 2. I can retrieve any document (as an owner of the website any document uploaded). 3. I need to have a search engine for all Hashs produced by the blockchain and get all infos for the submitter, like date, time and location and subject... (Please be aware as we are looking blockchain developer for a long term for multiple projects so for this project we shall not give any down payment/milestone as we shall award/payment/high rated feedback just after completion of job. But after this project i will always offer 50% advance payment and we shall build up your freelancer profile with good costing projects with high rated feedback as well.)