Looking for blockchain developer for multiple projects

I am looking for blockchain developer. 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... (I am looking for blockchain developer for a long term for multiuple projects so for this project i will not give any down payment or milestone as i will award/payment/high rated feedback just after completion and delivery. But after this project i will always offer 50% advance payment and i will buildup your freelancer profile with good costing projects with high rated feedback from my end.) Best of luck!!