You can read your DiceKey without the app. Before performing cryptographic operations seeded by your DiceKey, the app turns it into a 75-character string, with three characters representing each exposed face (die or sticker). The three characters are the capital letter and digit that appear on the face, followed by the orientation encoded as a lowercase letter ‘r’ (top facing top, or upright), ‘r’ (facing right, or rotated 90 degrees clockwise), ‘b’ (facing bottom, or rotated 180 degrees), or ‘b’ (facing left, or rotated 270 degrees clockwise).
However, you won't be able to generate secrets entirely by hand. To generate password, keys, and other secrets, the DiceKeys App uses an open-source cryptographic library to turn that 75-character string into secrets that don't reveal the DiceKey. That library is portable, open-source, and can be used independently of the app. You cannot generate secrets from your DiceKey by hand because there are no known functions for doing so that are both reliably computable by humans and considered secure by cryptographers.
Before performing cryptographic operations, the app rotates your DiceKey so that the top left face is the one with the letter earliest in the alphabet. For more information, see the specification.
The app uses recipes to turn your DiceKey into passwords, seeds, keys, and other secrets. It combines the recipe with your DiceKey using what is known as a one-way function. The one-way prevents someone who you share a generated secret with from learning the DiceKey you used to generate that secret. Even the tiniest change to your DiceKey or recipe will completely change the secret, so you will need both to re-generate more secrets in the future.
Because recipes are useless without your DiceKey, your recipe doesn't need to be kept secret. You can save it in the app and not worry that someone can access it, so long as they don't have your DiceKey. Unlike your DiceKey, your recipe will not be stored anywhere permanent and will be lost if you lose the device with the app in which your recipe is saved. That's why we try to encourage you to use very simple recipes that are easy to reproduce.
For example, if you need a password for your password manager or a major email provider, we probably already have a built-in recipe for you. If not, you can create a recipe just by pasting the URL or domain name of the site or app you need secrets for. You can add a sequence number if you need more than one recipe for the same application, but we recommend you only use numbers you can count on your fingers so that you can try them all if you forget which one you needed.
Your app is just a tool for using your DiceKey. You can get a new device, download the app, load in your DiceKey from its physical form, and be no worse off.
The only data you will lose are any recipes you have saved (see the above question about recipes). In most cases, re-generating a recipe should be as simple as picking from the list of built-in recipes or copying the URL or domain name of the site you need a password or secret for into the recipe builder.