Guard7
Version 1.2

Guard7 is a general purpose cryptography tool that used to encrypt or decrypt email, file, sign and verify files. It is the graphical frontend for the GNU Privacy Guard (GnuPG or GPG, http://www.gnupg.org) on macOS (previously Mac OS X) with additional features. Guard7 is an encryption and decryption system based on industry standard that can ensure the complete security of business negotiations or personal messages. It was developed to make the daily work with GnuPG on macOS easy and simple.

It's free!





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Why

The most difference between "public key cryptography" and normal "password protected cryptography" is that the first approach don't ask you to distribute any password to anyone or any unsafe place, e.g. email, chat app, or internet. That is, you send an encrypted message or file to someone, but don't need send any password to him/her. And the most important point is, you need an encryption tool that has industrial strength to protect your confidential information.

General Features

Basic Usage

You don't need to know more about public-key encryption at all, you can get industry-level information protection with just a few simple steps.

  1. Generate a key pair for yourself.
    Click and the system will generate a public and private key pair for you. You should send the public key to others who can then encrypt message for you. The private key is used to decrypt message and must be keeping for yourself. You SHOULD NOT send your private key to anybody, but keep it for yourself VERY CAREFULLY.

    Note: This operation is very time-consuming, please wait a while with patient.

  2. Distribute your public key.
    Select your key, right click the node and then select "Export Public Key", your public key file will be created. Put your public key in a GPG server, your web site or send it directly to others via chat app, email or other channel.

  3. Import other people's public key.
    Ask someone else to send his public key to you, or if he has already distributed his public key on GPG server, you need to download it and then simply drag the key file into the left side treeview to import it.

    click the "+" symbol or click and then select the "Import Public Key" menu or directly drag the key file into the left side treeview to complete the operation.

  4. Use other people's public key to encrypt message, and then sent to them.
    Drag their email (public key) into the right side drop-area as recipients, and then encrypt your message or file.

  5. Decrypt message with your own private key.
    If someone else has your public key, they can encrypt message with your public key, and then you can decrypt the message with your private key. When you decrypt a message or file, or verify file signature, you don't required to do any extra actions. The system will automatically use the default master key that you set to do the operation, i.e., you don't need to choose your own private key manually.

Encrypt or sign file follows the same steps and principles.

Group Contacts

Organise your contacts by company and department.

Note: Drag operation only available for the primary keys that always display an email address.

File Types

Name Rules
Public key has format: xx@xx_pubkey.asc.
Private key has format: xx@xx_privkey.asc.



Encrypt File

  1. Drag the file into the right side drop-area.
  2. Drag the recipients from left side treeview into the right side drop-area, repeat this operation to add more recipients.
  3. Click on the Toolbar.
  4. Select the output directory.

Note: It's not necessary to compress file before encrypt it, because Guard7 will compress it automatically.

Decrypt File

  1. Drag the file into drop-area.
  2. Click on the Toolbar.
  3. Select the output directory.


Encrypt and Decrypt Email

Sender

  1. Drag the recipients from the left side treeview into the right side drop-area.
  2. Click on the Toolbar to open mail box.
  3. Input your text in the mail box.
  4. Ensure the "Attach to email" checked.
  5. Click "Encrypt"
  6. The engine will launch the built-in Mail app of macOS and create a mail automatically.
  7. The content of the encrypted message will be attached in the mail with .gml extension name.
    Tips: Use Up/Down arrow key to select multiple recipients.

Receiver

  1. Launch the macOS's built-in Mail app of macOS if it haven't opened.
  2. Select the mail that you want to view in Inbox.
  3. Click on the Toolbar to open mail box.
  4. Click "Decrypt"
  5. Guard7 will decrypt the message attached in the selected email that has a .gml extension name.

View message file without open Mail App



Encrypt and Decrypt Plain Text

Sender

  1. Drag the recipients from left side treeview into drop-area.
  2. Click on the Toolbar to open mail box.
  3. Input your text in the mail box.
  4. Uncheck the "Attach to email".
  5. Click "Encrypt".
  6. The engine will produce text with two marks, begin with "-----BEGIN PGP MESSAGE-----" and end with "-----END PGP MESSAGE-----".
  7. Carefully copy the content and paste it into Web Mail (e.g. Gmail, Yahoo! Mail), Chat Apps (such as Jabber, ICQ, Skype, Viber, Google Hangouts, WhatsApp, LINE, Discord, Ventrilo, TeamSpeak, Kik, Slack, Telegram, etc), any software that you want to translate your confidential message.
    Note: please ensure the begin and end mark included.

Receiver

  1. Click on the Toolbar to open mail box.
  2. Past text that has "-----BEGIN PGP MESSAGE-----" and "-----END PGP MESSAGE-----" marks.
  3. Uncheck the "Attach to email".
  4. Click "Decrypt".
  5. The engine will decode the message and output the result in the mail box.

With the help of Guard7 you can encrypt any text message and send it in any way convenient for you.



Sign File

  1. Drag the file into the right side drop-area.
  2. Drag your primary key from left side treeview into the right side drop-area.
  3. Click on the Toolbar.
  4. Select the output directory.

Verify File

  1. Drag the file into the right side drop-area.
  2. Click on the Toolbar.
  3. Select the location (directory) of the signed file, normally it should together with the signature file in the same directory.


Recipients Organisation

  1. Drag single key or several group form left side treeview into drop-area, single key means an individual and a group means all recipients in it.
  2. Right click to see more details of the selected key.
  3. Right click to remove some recipients.

Drag multiple groups into the drop-area enable you quickly organise dozens of recipients to receive your file or message. But if you use a command line software or other tools, you will have to organise the recipients one by one, it's very time waste and boring.

Operation with Finder

  1. Drag key file into the left side treeview then it will be imported.
  2. Drag encrypted file, signature file or message into the right side drop-area then you can decrypt, verify or read them.
  3. Select key file, signature file, encrypted file or message in Finder, right click "Open With" then you can import key, verify, decrypt or read the message.

Keyring Management

keyring is a package working like a folder that binding group info, public and private key together, it's a common compressed zip file when you export a keyring. The system will automatically create a keyring named as "home" for you if there's no any keyring exists when you run Guard7 at the first time.

Click "Preferences" on main menu.

  1. Create new keyring.
    When your contacts are too many, such as hundreds or even thousands, or other reasons you need to create a separate keyring for a large number of contacts.

  2. Import or export keyring.
    You need to import keyring from other system, e.g. Linux, and when backup or change hardware you need to export keyring. Please compress your ~/.gpg on Linux as a tar file when you want to import it into Guard7.

  3. Switch keyring.
    keyring enable you to organise group of contacts like folder and can conveniently switch between them.

Key Management

  1. Never send your private key to others.
  2. Keep your private key on a USB drive is a good method, but print it on paper and lock it in a safe will be more reliable.
  3. Backup your keyring carefully.
  4. Sign and encrypt messages with your subkey.
  5. Sign and encrypt files with your subkey.
  6. Verify a key in an efficient way is, directly make a phone call and ask he/she read out the fingerprint of his/her key.

subkey: the subnode under your primary key node (the node titled with your email address).

Edit Key (optional)

Note: edit key is not necessary in daily usage scenario.



Simple Demonstration Session

The following steps emulate a session between two person on a same machine, here assume the two person are Tom and Mary, the steps can help you get an overview understanding of how "Public Key Cryptography" works.

Step 1. Create keypair for Tom and Mary:

a. Click "GenKeys" on toolbar to generate a key pair for Tom.
b. Select the created key and export Tom's public key and private key.
c. Click "GenKeys" on toolbar to generate a key pair for Mary.
d. Select the created key and export Mary's public key and private key.
Please give the key pair an easily remember password for test only.

Now, you have four key files:
Tom@compnay_pubkey.asc
Tom@compnay_privkey.asc
Mary@compnay_pubkey.asc
Mary@compnay_privkey.asc


Step 2. Tom create a crypted file with Mary's public key:

a. Right click Tom's public key and then select "Edit Key", input password and on the prompt dialog select "Primary", check on "set as your primary key" and click "Set as primary key" button.
b. Remove all key of Mary from the left side tree view.
c. Drag Mary@compnay_pubkey.asc into the left side tree view to emulate importing Mary's public key.
d. Drag the Mary's public key imported in the previous step from left side to the right side table as a Recipients.
e. Drag a sample file from Finder into the right side table and then click "Encrypt" on the toolbar to crypt it, a compressed file with ".gpg" extension name will be created.

Step 3. Mary decrypt the file with her private key:

a. Remove all key from the left side tree view.
b. Drag Mary@compnay_pubkey.asc into the left side tree view to import Mary's public key.
c. Drag Mary@compnay_privkey.asc into the left side tree view to import Mary's private key.
d. Right click Mary's public key and then select "Edit Key", input password and on the prompt dialog select "Primary", check on "set as your primary key" and click "Set as primary key" button.
e. Drag the crypted file output from step 2 and then click "Decrypt" on the toolbar to decrypt it.



Guard7 on Apple App Store

This cryptography tool is one of the top best-sales security app on App Store from 2018, thousands of copy have been downloaded from that time and people across the planet use it to protect their confidential information everyday.

Note: One thing you must know is, they do very bad things on Apple App Store, these gentlemen leaves bad comments on the "rate and comment" of some good apps or vice versa to mislead people, so please judge one app's value by yourself instead of what they said.

The more they maliciously attack this software, the more their bad intention are exposed, and the more affirmation of this software.

Feedback

Feature request and issue management on Github:
→ https://github.com/chengdu/Guard7, thanks.

Need Your Help

There're several graphical frontend for GnuPG was proposed to running on other platforms and will be released as free software forever, including Windows, Linux, iOS and Android, the author of Guard7 can make them but no enough time to accomplish them, please contact us if you're interested in making any one of them and willing to do contribution to free software world.

Why Guard7 is free?

Mac OS X should has such a valuable and useful tool like Guard7 that can encrypt confidential information simple, easy and free.

Thanks

Here sincerely thanks the authors and contributors of GNU Privacy Guard, for your excellent works.

References

  1. GNU Privacy Guard, http://www.gnupg.org.
  2. Public key cryptography on Wikipedia, Public-key Cryptography.