Day One Mac
The Mac version of Day One allows you to set a private security passcode. For optimal security, it is important to have a private user login to your device (that you do not share with others). Read Mac OS X: Setting Up User Accounts for more information on setting up individual accounts on your Mac.
In a future release of the Day One 2 app, we will be supporting end-to-end encryption. Our encryption features will utilize the user's private key to encrypt all entries before they reach the server. In short, the server will have no access to the user's unencrypted data. Neither iCloud nor Dropbox currently provide this level of security (see: https://support.apple.com/en-us/HT202303 and https://www.dropbox.com/help/28, respectively), thus making Day One Sync even more secure than these other sync/backup methods. If you would like to encrypt your data today, you can use Apple's FileVault service.
Day One iOS
Like the Mac version, you can enable a Day One passcode to restrict usage to yourself or those with whom you share the passcode. Follow these steps:
- Open Day One.
- Tap Settings, then tap the Passcode/Touch ID.
- Enter and verify your passcode.
- By default, your passcode will be required whenever you leave Day One or your device goes to sleep. Tap "Immediately" to choose other frequency options for your passcode.
To encrypt your data on your iOS device, you can enable a passcode for your device (this is different from the preceding Day One passcode). To do this, follow these steps:
- Go to Settings > General.
- Tap "Passcode".
- Tap "Turn Passcode On".
For more information, read Apple's support article, Understanding Data Protection.
With Day One, if you sync data between multiple devices using Dropbox and iCloud, your data relies upon the privacy/security measures Dropbox and iCloud implement. Please see the policies and statements by iCloud and Dropbox for more details.