- •Contents
- •3 How Gpg4win works
- •4 The passphrase
- •5 Two methods, one goal: OpenPGP & S/MIME
- •6 Installing Gpg4win
- •8.1 Publishing per e-mail, with practice for OpenPGP
- •12 Encrypting e-mails
- •13 Signing e-mails
- •13.1 Signing with GpgOL
- •13.2 Checking signatures with GpgOL
- •13.3 Reasons for a broken signature
- •13.4 Encryption and signature
- •14 Archiving e-mails in an encrypted form
- •19.1 Export
- •19.2 Import
- •21 Known problems and help
- •21.1 GpgOL menus and dialogs no longer found in Outlook
- •21.2 GpgOL buttons are not on the Outlook 2003 toolbar
- •21.4 Errors when starting GpgOL
- •21.5 Installation of Gpg4win on a virtual drive
- •21.8 S/MIME operations not allowed (CRLs not available)
- •22 Files and settings in Gpg4win
- •22.1 Personal user settings
- •24 Why Gpg4win cannot be broken ...
- •25 GnuPG and the mystery of large numbers
- •25.1 Calcualting with residue classes
- •25.2 RSA algorithm and calculating with residue classes
- •25.3 RSA encryption with small numbers
- •25.4 Display using different base numbers
- •B Using GnuPG with other e-mail programs
- •C Automatic installation of Gpg4win
- •D Transfer from other programs
- •E Uninstalling Gpg4win
- •G GNU Free Documentation License
- •Index
24 Why Gpg4win cannot be broken ...
... at least not with currently known methods, and provided the software is free of errors.
In reality however, it is precisely those errors in the programs that provide opportunities for obtaining secret information when the software is used, or errors that are contained in the operating system. Free software on the other hand offers virtually the best prerequisites to avoid these types of errors.
Each example in this compendium has shown that there is a connection between the private and public key. Secret messages can only be decrypted if both match.
You do not really have to know the secret behind this mathematical connection – Gpg4win will also work without it. At the same time, even laymen can understand this complex mathematical method, since it only uses basic arithmetic methods (addition, subtraction, multiplication and division) in order to define a special kind of addition and multiplication. The fact that there are no secret methods and algorithms is what is behind the security philosophy of cryptography and the principle of Free Software. Finally, this is also the best way of really understanding why GnuPG (the actual machinery behind Gpg4win) is so secure.
In other words, this is where the free program that follows the compulsory portion begins.
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