I am currently using the structure and mapping to store the user data in the blockchain. In the mapping I am using user's address (msg.sender) for mapping it with structure so every user can only access his/her data on the base of ethereum account.
struct User{
byte32 fname;
byte32 lname;
byte32 email;
}
mapping(address => User) UserData;
I read about the function name
web3.eth.getStorageAt
that can return the data at the particular storage point,I want to know what level of data security i could achieve as i am also making the dapp.