Lock your notes on iPod touch
In the Notes app 
, you can lock notes to protect your sensitive information with a password. Notes uses a single password for all your locked notes, on all of your devices.
Set a password to unlock your notes
The password you set applies to all notes you lock from now on. Notes that already have a password aren’t affected.
Go to Settings
> Notes > Password.Enter a password.
If you forget your notes password, you can reset it. Go to Settings > Notes > Password > Reset Password. The new password applies to all notes you lock from now on, but it doesn’t give you access to your previously locked notes.
See the Apple Support article Lock notes on your iPhone, iPad, iPod touch, and Mac.
Lock a note
You can only lock notes on your device and notes in iCloud. You can’t lock notes that have PDFs, audio, video, Keynote, Pages, Numbers documents attached, or notes that sync with other accounts. You can’t lock an iCloud note that has collaborators.
Open the note you want to lock.
Tap
, then tap Lock Note.When a note is locked, the title remains visible in the notes list.
To remove a lock from a note, tap , then tap Remove Lock.
Open a locked note
Unlocking one note unlocks all your notes for several minutes so you can easily jump into another note or copy and paste information from other apps.
Tap the locked note, then tap View Note.
Unlock it with your Notes password.
To lock your notes again, do one of the following:
Tap the lock icon at the top of the screen.
Tap Lock Now at the bottom of the notes list.
Close the Notes app.
Lock your iPod touch.