Ok, I am in a little bit of cryptographical fix :D
I need to figure out a way to encrypt and decrypt data handled by a website. The website is intended only for a certain group of people who will use it to upload and search sensitive information.
Data is entered by them using a browser, which should be encrypted before sending and storing it in the server/database.
On the other hand when these users search for a value (say, account number) in the database, it is queried whether present in the database and if yes, it is decrypted and displayed on the browser.
The whole point of encryption/decryption is to make sure that website hosters, owners and administrators do not understand the data values.
It is a website that has multiple users who might be accessing the same data/values from the same database. If we have 1000 registered users, the information uploaded by each of them should be available to all of the 1000 users.
The problem here is that this is not a person to person encryption/decryption (like sending an encrypted email), therefore I am not sure if the private and public key cryptography can be implemented in it's raw form. What is the logical way to implement cryptography in this situation?