NouveauPG allows you to securely message others using iPhone apps you already have. You use the clipboard to efficiently shuffle encrypted messages into and out of your favorite messaging and e-mail apps.
Before you can receive (and decrypt) any encrypted messages, you must first generate an identity. An identity is sometimes referred to as a key pair or public/private key pair. Your identity has a public part that can and should be distributed to anyone that might want to send you an encrypted message. The private part of your identity is used to decrypt messages that were encrypted using the public part of the identity.
The private portion of the identity is further protected by a password. Even if you have the password for an identity, you can’t decrypt a message without the private key. The password is just another line of defense against unauthorized access to the private key.
It will take a few moments to generate a new identity, depending on how recent your iPhone is.
Clicking on your newly created identity will bring up a short menu. You can export a public key certificate for this identity, which others will use to encrypt messages for the identity.
From this screen you can either e-mail this public key certificate someone that may want to send you an encrypted message or copy and paste into another app.
You can also add this public key certificate to your Recipients list and be able to encrypt messages to yourself. This may help you understand the OpenPGP process better by examining from end to end.
As usual, you can easily send the encrypted message to the e-mail address specified in the public key certificate. But since you’re sending the message to yourself, simply save it to your Messages. (The Save button on the toolbar)
The messages is where encrypted messages are stored waiting to be decrypted. The add icon on the upper left will add an empty message. You can paste an encrypted OpenPGP message into this empty message and NouveauPG will automatically recognize if it is encrypted for the public key of an Identity.
If NouveauPG recognizes the Identity the message was encrypted for, it’s identicon will appear on the left side of the cell. Otherwise, a preview of the message’s content will show instead.
Once you select an encrypted message, you have the option of attempting to decrypt the message.
First you must unlock the private part of identity with the password you selected.
This is known as “unlocking the keystore.” The key store is always protected by a password as a line of defense against unauthorized access to the key.
Once you unlock an identity, the menu has a couple more options. Exporting the private keystore will allow you to use import this identity into NouveauPG on another device or NouveauPG for Mac OS. If you intend on using a key for a period of time, you would be well advised to export and backup a private keystore for the identity. You will be prompted for a password to protect the keystore with.
Now that you have unlocked the identity, you are able to freely decrypt the OpenPGP messages encrypted for that identity.