Gestures and Unicode Input

Alexander E Genaud alex.list at genaud.org
Fri Mar 23 00:42:42 CET 2007


[Gestures and Unicode Input]

> > Ben Burdette wrote:
> > But for password entry it seems very insecure.  I mean,
> > wouldn't entering a password with gestures be like
> > sending secret messages with signal flags? Anyone
> > who knows the system could just read what you
> > were entering.
>
> Gilles Casse wrote:
> The gesture could be done eyes-free the phone hidden in a pocket.
> The touch screen could hopefully be used as a chord keyboard with
> speech feedback thanks to the eSpeak voice synthesizer.

I don't think the gestures should, by default, be displayed on the
screen. Considering the Neo has a touch screen interface, there may
not be a better defense against shoulder snooping onlookers than
gestures. Without tactile feedback the user would best input patterns
rather than selecting from keys displayed on the screen.

I was not suggesting that the 3x3 grid be displayed on the screen. The
grid only helps to describe patterns (the four rotations and 2
reflections (8) of an 'L' shape, for example). I wasn't thinking so
much of password input as a general method of entering character
points in the Unicode range -- some cross between Graffiti and a UTF-8
stream.

Here's one of possible encoding. Suppose we had 40 distinct symbols.
Let's reserve 32 trailing symbols and define 8 leading symbols.
4 distinct symbols lead a single trailing symbol
3 distinct symbols lead three trailing symbols
1 distinct symbol leads five trailing symbols

(32-35) (00-31)
(36-38) (00-31) (00-31) (00-31)
(39)      (00-31) (00-31) (00-31) (00-31)

 4 * 32^1 =     128 (ASCII range)
  3 * 32^3 =   98304 (more than the 2 byte BMP)
 1 * 32^4 = 1048576 (multi-plane Unicode)
-------------------
            1147008 character points

Where
Unicode   = 1114111 character points

I previously came up with 48 distinct symbols, so there is some play
room. Perhaps this is all nonsense, though I don't think we'd have
hand-writing recognition for the entire Unicode range any time soon.

Alex

-- 
 亚 |      alex at genaud.net
 历 |      http://genaud.net
 山 | GPS:  [ 55.67N 12.588E ]
  大 | PGP: CCC7 D19D D107 F079 2F3D BF97 8443 DB5A 6DB8 9CE1


More information about the community mailing list