Re: Unicode and Security

From: John Cowan (cowan@mercury.ccil.org)
Date: Mon Feb 04 2002 - 06:15:25 EST


Gaspar Sinai scripsit:

> So common language is screenshots... Ok. I updated the page.

Thank you.

> Now the exact same file is viewed with two different viewers
> at the bottom of this page:
>
> http://www.yudit.org/security/

Outlook Express, at least the version you are using, has a bug;
it is failing to set the overall directionality to RTL even
though the first character is strongly RTL. The fact that
some implementations are buggy is hardly an argument against
either the use of bidi or Unicode.

Furthermore, the example is perverse: you are providing
a sentence that looks like it's meant to be read as
English, but in Arabic reading order.

> I maintain my view that if there is no proven
> reversable logical-to-viewed/viewed-to-logical
> electronic signatures should be avoided.

There is nothing to be done about the fact that
the visual appearance

        the Arabs = BARA-LA
        Islam = MALSI-LA

(using caps for RTL as usual) can be read as either
Arabic-to-English or English-to-Arabic, depending on
the larger context. If you saw it written down in
isolation, you wouldn't know which way to read it
either: nothing in the mere appearance of such a text
tells you whether it is basically in English or Arabic.
Therefore, this appearance can have either of two
encodings:

        AL-ARAB = the Arabs\nAL-ISLAM = Islam
        the Arabs = AL-ARAB\nIslam = AL-ISLAM

-- 
John Cowan           http://www.ccil.org/~cowan              cowan@ccil.org
To say that Bilbo's breath was taken away is no description at all.  There
are no words left to express his staggerment, since Men changed the language
that they learned of elves in the days when all the world was wonderful.
        --_The Hobbit_



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