Here's how the system works:
2.
The transponder broadcasts a signal back to the lane antenna with some basic
information.
3.
That information is transferred from the lane antenna to the central database.
4.
If the account is in good standing, a toll is deducted from the driver's
prepaid account.
5.
If the toll lane has a gate, the gate opens.
6. A green light indicates that
the driver can proceed. Some lanes have text messages that inform drivers of the
toll just paid and their account balance.
The entire process takes a
matter of seconds to complete. The electronic system records each toll
transaction, including the time, date, plaza and toll charge of each vehicle.
Typically, consumers maintain prepaid accounts.A yellow light or some other
signal will flash to indicate if an account is low or depleted.
The rules regarding how fast
you can pass through the toll plaza vary from system to system. Some traffic
agencies allow drivers to pass through the system at 55 miles per hour (86
kph). Others want you to slow down to 30 mph (48 kph), or even 5 mph (8 kph).
These lanes
are monitored using video cameras. Some states allow cars to drive right
through the toll plaza as the antenna detects the transponder. If you try to go
through the plaza without a transponder, the camera records you and takes a
snapshot of your license plate. The vehicle owner then receives a violation
notice in the mail.
How Encryption Works
Information security is
provided on computers and over the Internet by a variety of methods. A simple
but straightforward security method is to only keep sensitive information on
removable storage media like floppy disks. But the most popular forms of
security all rely on encryption, the process of encoding information in such a
way that only the person (or computer) with the key can decode it.
Computer encryption is based on
the science of cryptography, which has been used throughout history. Before the
digital age, the biggest users of cryptography were governments, particularly
for military purposes. The existence of coded messages has been verified as far
back as the Roman Empire. But most forms of cryptography in use these days rely
on computers, simply because a human-based code is too easy for a computer to
crack.
Most computer encryption
systems belong in one of two categories:-
Symmetric-key encryption
Public-key encryption
Symmetric Key
In symmetric-key encryption, each computer has a
secret key (code) that it can use to encrypt a packet of information before it
is sent over the network to another computer. Symmetric-key requires that you
know which computers will be talking to each other so you can install the key
on each one. Symmetric-key encryption is essentially the same as a secret code
that each of the two computers must know in order to decode the information.
The code provides the key to decoding the message. Think of it like this: You
create a coded message to send to a friend in which each letter is substituted
with the letter that is two down from it in the alphabet. So "A"
becomes "C," and "B" becomes "D". You have
already told a trusted friend that the code is "Shift by 2". Your
friend gets the message and decodes it. Anyone else who sees the message will
see only nonsense
Public Key
Public-key encryption uses a
combination of a private key and a public key. The private key is known only to
your computer, while the public key is given by your computer to any computer
that wants to communicate securely with it. To decode an encrypted message, a
computer must use the public key, provided by the originating computer, and its
own private key. A very popular public-key encryption utility is called Pretty
Good Privacy (PGP), which allows you to encrypt almost anything. You can find
out more about PGP at the PGP site.
To implement public-key
encryption on a large scale, such as a secure Web server might need, requires a
different approach. This is where digital certificates come in. A digital
certificate is basically a bit of information that says that the Web server is
trusted by an independent source known as a certificate authority. The
certificate authority acts as a middleman that both computers trust. It
confirms that each computer is in fact who it says it is, and then provides the
public keys of each computer to the other.
A popular
implementation of public-key encryption is the Secure Sockets Layer (SSL).
Originally developed by Netscape, SSL is an Internet security protocol used by
Internet browsers and Web servers to transmit sensitive information. SSL
recently became part of an overall security protocol known as Transport Layer
Security (TLS).
Look for the "s"
after "http" in the address whenever you are about to enter sensitive
information, such as a credit-card number, into a form on a Web site.
In your
browser, you can tell when you are using a secure protocol, such as TLS, in a
couple of different ways. You will notice that the "http" in the
address line is replaced with "https," and you should see a small
padlock in the status bar at the bottom of the browser window.
Public-key
encryption takes a lot of computing, so most systems use a combination of
public-key and symmetry. When two computers initiate a secure session, one
computer creates a symmetric key and sends it to the other computer using
public-key encryption. The two computers can then communicate using
symmetric-key encryption. Once the session is finished, each computer discards
the symmetric key used for that session. Any additional sessions require that a
new symmetric key be created, and the process is repeated.
NEXT COMING:::ARE YOU AUTHENTIC?
