The solution would be to get a secret keeper applications, which will store your confidential information in a ciphred state, and under the protection of a password known only by you. For Apple systems, there are several applications which can do this, and among them there are PasswordWallet, Wallet, and SplashID, just a few examples.They encrypt data on your iPhone, and it can be accessed only with a password. These softwares let you make some categories for the data you would like to encrypt and you can make the difference between the logins and credit card numbers, or insurance numbers.
I would like to tell you about three iPhone password applications I found in the App Store, and I can say that one is free and it's quite good, one has a very good management database system and the other one offers the possibility to sync the encrypted data in the phone with a computer.
LockBox is a secret tracker, a simple application, perfect designed for people with basic needs. You can have a number password, but it can be as long as you want. This software organizes the encrypted information in six categories and in all categories, the fields are the same: title, information (on two lines) and notes (three lines). It doesnt have a special field for URL's or for Credit Card Numbers. It doesn't offer the possibility of sorting the entries, or searching among the encrypted information. If you have basic needs, and you don't need a complex, expensive solution, it's perfect for you.
eWallet is a great solution for people who pay attention to details, and like to organize very deep their information. There are more storage areas, and they are called wallets, and here comes the name of the application. Each wallet has a password and you can create more categories inside each area. There are customizable fields, and you can adapt them to the card types you have, so it can easily adapt to your needs. The fields have many subfields, depending on their type, and for example, for the e-mail field you have: user, password, server and other 10 fields to fill in as you wish. The fields are smart, and you can tap URL fields and Safari launches. In the same manner, e-mail and phone number areas can be tapped and they do what you expect. eWallet has its minuses, and one of them is the lack of a search function, but the ability of creating more wallets and categories offers a good organization until the collection enlarges. This application is very good if you want the ultimate software in controlling your secret information on iPhone.
If you want to keep your secret information in two places, on the computer and on the iPhone, you don't have to duplicate the information in different files and then organize them yourself. For this, there is SplashID from SplashData, which can sync the encrypted data on the iPhone with your Mac/your desktop computer. The desktop version costs $20 and the other organizing attributes are as good as eWallet's. SplashID has a simpler user interface, but eWallet has a good management system. SplashID is very functional and it is great that it can sync the iPhone with the home computer.
I strongly recommend you to use a password application if you want to store personal information on your iPhone!
Later edit: We received an e-mail from an Ilium Software representative and they have a few things to add at our description about eWallet :
"eWallet does have a search function - if you look to the bottom of every screen, you'll see a little magnifying glass icon. If you click that icon, it brings up a search bar where you can type in whatever you're looking for. Also, while we don't have a Mac version yet, we do have a Windows PC version that will sync with the iPhone. It costs $9.95 to add on. You can also use it in Parallels on a Mac. We are currently working on a Mac version as well." - Julie Van De Water.