Tizen Developers

Hi~ 

Please read about the web storage security

1. http://stackoverflow.com/questions/3718349/html5-localstorage-security

2. http://softwareengineering.stackexchange.com/questions/74155/how-secure-is-localstorage

My suggestion:

You can make your whole data a json and encrypt with a password. And then store. 

You can use Stanford Javascript Crypto Library for encryption/decryption. 

For Ex, 

var yourJson = {"employees":[
    {"firstName":"John", "lastName":"Doe"},
    {"firstName":"Anna", "lastName":"Smith"},
    {"firstName":"Peter", "lastName":"Jones"}
]};

var stringData = JSON.stringify(yourJson);

//encryption
var dataTobeStored = sjcl.encrypt("YourPassword", stringData);

//storing to local storage
localStorage.setItem("YOUR_KEY_FOR_SAVING", dataTobeStored);

// retrieve from local storage
var storedEncryptedData = localStorage.getItem("YOUR_KEY_FOR_SAVING");

// decrypt
var storedStringData = sjcl.decrypt("YourPassword", "storedEncryptedData");

var yourJsonAgain = JSON.parse(storedStringData);

SJCL Ref: http://bitwiseshiftleft.github.io/sjcl/

SJCL Demo: http://bitwiseshiftleft.github.io/sjcl/demo/

Hope it will help you! 

Cheers