```                    CHARLIE
(thoughtfully)
We could apply frequency-domain
processors.  Larry can help, he worked
with the NSA on noise analysis...
```

# Filtering a White Noise Sequence »

This Demonstration creates a white-noise sequence and then uses a low-pass filter to produce a red-noise sequence. The "filter cut-off" is the fractional point in [0, 1] on the spectral frequency axis to apply the filter, as measured from zero frequency. The rate of suppression of frequencies larger than the filter cut-off is given by the "filter roll-off" exponent n (1 to 4); larger values of n mean greater suppression of the higher frequencies. A new time sequence is generated with the "randomize" button. The amplitude spectrum of the time series is plotted simultaneously, with spectral values on a log scale, out to the Nyquist frequency.
```Where one computer shows the restaurant's plain password
request page, and another is filled with computer code, which
the FBI has started to decipher.

DON
Amita, that's the restaurant's
computer hard drive...

AMITA
Multi-layer encryption...

DON
Our techs could crack it -- but
you're faster and I don't have a lot
of time.
```

# Strong RSA Cryptosystem »

The RSA cryptosystem was invented by R. Rivest, A. Shamir, and L. Adleman. This Demonstration 1) generates a large RSA modulus n (up to 700 decimal digits); 2) creates the corresponding public and private keys, e and d; 3) provides a simple, practical way to encrypt and decrypt messages in various UNICODE supported languages.
```                    CHARLIE (cont'd)
Same in audiology.  We shrink sounds
we don't want so the sound we do want
becomes foreground.

LARRY
We use filters to diminish or blur
noise -- identifying each unwanted
sound by its frequency, then
discriminating against it.
```

# Geometric Mean Filtering for Blurring »

The geometric mean filter is a member of a set of nonlinear filters that are used to remove Gaussian noise. It operates by replacing each pixel by the geometric mean of the values in its neighborhood.
```                    LARRY
(intrigued)
Or under the squares.
(tries some keys)
Like a dragon hiding in its lair.
Seems Yoon had a thing for numbers 8
and 9.

AMITA
I've tried every number, and every
combination of number.
```

# Probabilities of Combinations »

After selecting the colors using the controls, imagine that one color is picked at random from each disk. The order of the combination of colors is not important; for example, red, blue, orange is considered the same combination as red, orange, blue.