Store confidential information securely using Keychain Access on Mac
You can use Secure Notes in Keychain Access to store confidential information. This information can be completely unrelated to your computer, such as combinations to locks, personal identification numbers (PINs) for bank accounts, credit card numbers, confidential notes, cryptographic keys, and any other information that you want to keep private.
Create a Secure Note
In the Keychain Access app on your Mac, select a keychain in the Keychains list.
If you’re not sure which keychain to pick, it’s recommended that you use iCloud Keychain to store secure notes. Notes that you create are available and updated across your devices (when you’re signed in with your Apple ID).
Choose File > New Secure Note Item.
Type a name for the note to help you remember what it is.
In the Note field, type or paste the information you want to preserve.
View the contents of a Secure Note
In the Keychain Access app on your Mac, select Secure Notes in the Category list.
Double-click the note, then select the Show Note checkbox.
You are asked for your keychain password if you haven’t selected “Allow all applications to access this item” in the Access Control pane.
Type your login password to see the note, then click Allow or “Always allow.”
If you want this note to be secure, don’t click “Always allow.”