Red Hat DIRECTORY SERVER 8.1 - 11-01-2010 Manual de usuario descargar pdf (Pagina 100)

Each letter of the passphrase is the first letter of each word. In the first

line, the number is written in figures instead of being spelt out. In the

second line, the name of the protagonist of the song is in uppercase

letters. Each verse is separated by a slash, and a final dot is added.

You can make up the rules as you prefer.

Another possible passphrase would be

HwmyrsmtBeyuclhm?

This one comes from Bob Dylan's Blowin' In The Wind, and is derived

from the first and last letter of each word, considering only the first four of

each verse:

“How many roads must a man walk down

Before you call him a man?”

These are the strongest passphrases, as they look like random

sequences of letters.

You can use an existing quote, and make up the rules to transform it in a

passphrase; should you ever forget the quote, a quick look on a book will

solve the problem. You may also invent your own quote, although in this

case forgetting it would be fatal.

12.2. Protection of the local machine

You should be aware of the truth that your encrypted mails are as safe as

allowed by the computer you use Enigmail on. This point can never be stressed

enough.

If your machine is infected with a keylogger and a malware that grants an

intruder remote access on your files, all the cryptographic robustness of

OpenPGP and the strongest passphrase won't protect your messages from

being snooped or falsified. In a similar way, if you leave your computer

unattended with your passphrase cached on, prepare yourself for nasty

surprises. In fact, even using cryptography, your communications cannot be

secure if your machine isn't. Even worse, cryptography could lure you into a

false sense of security, making you more prone to share sensitive information

via email.

The ciphers OpenPGP uses are the strongest known, and OpenPGP encryption

is virtually unbreakable if done in the right way. However, there are a lot of

other things that can go wrong.

The well-established fact that OpenPGP is the strongest link in the chain of

security simply means that an attacker wanting to read your encrypted

messages won't try to brute-force the encryption (which would take millions of

years), but will focus on other weaknesses instead.

He might break into your computer and steal your secret key. Then, infect your

computer with a spyware to record your passphrase, or directly record your

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Red Hat DIRECTORY SERVER 8.1 - 11-01-2010 Manual de usuario Pagina 100