Are You
Authentic?
As stated
earlier,encryption is the process of taking all of the data that one computer
is sending to another and encoding it into a form that only the other computer
will be able to decode. Another process, authentication, is used to verify that
the information comes from a trusted source. Basically, if information is "authentic,"
you know who created it and you know that it has not been altered in any way
since that person created it. These two processes, encryption and
authentication, work hand-in-hand to create a secure environment. There are
several ways to authenticate a person or information on a computer:
Password - The use of a user name and password
provides the most common form of authentication. You enter your name and
password when prompted by the computer. It checks the pair against a secure
file to confirm. If either the name or the password does not match, then you
are not allowed further access.
Pass cards - These cards can range from a simple card
with a magnetic strip, similar to a credit card, to sophisticated smart cards
that have an embedded computer chip.
Digital signatures - A digital signature is basically
a way to ensure that an electronic document (e-mail, spreadsheet, text file) is
authentic.The Digital Signature Standard (DSS) is based on a type of public-key
encryption method that uses the Digital Signature Algorithm (DSA). DSS is the
format for digital signatures that has been endorsed by the U.S. government.
The DSA algorithm consists of a private key, known only by the originator of
the document (the signer), and a public key.The public key has four parts,
which you can learn more about at this page. If anything at all is changed in
the document after the digital signature is attached to it, it changes the
value that the digital signature compares to, rendering the signature invalid.
Recently, more sophisticated
forms of authentication have begun to show up on home and office computer
systems. Most of these new systems use some form of biometrics for
authentication. Biometrics uses biological information to verify identity.
Biometric authentication methods include:
Fingerprint scan
Retina scan
Face scan
Voice identification
Another secure-computing need
is to ensure that the data has not been corrupted during transmission or
encryption. There are a couple of popular ways to do this:
Checksum - Probably one of the oldest methods of
ensuring that data is correct, checksums also provide a form of authentication
because an invalid checksum suggests that the data has been compromised in some
fashion. A checksum is determined in one of two ways. Let's say the checksum of
a packet is 1 byte long. A byte is made up of 8 bits, and each bit can be in
one of two states, leading to a total of 256 (28 ) possible combinations.Since
the first combination equals zero, a byte can have a maximum value of 255.
§If the sum of the other bytes in the packet is 255 or
less, then the checksum contains that exact value.
§If the
sum of the other bytes is more than 255, then the checksum is the remainder of
the total value after it has been divided by 256.
Byte
1
|
Byte
2
|
Byte
3
|
Byte
4
|
Byte
5
|
Byte
6
|
Byte
7
|
Byte
8
|
Total
|
Checksum
|
||
212
|
232
|
54
|
135
|
244
|
15
|
179
|
80
|
1,151
|
127
|
||
1,151 / 256 = 4.496 (round to 4)
4 x 256 = 1,024
1,151 - 1,024 = 127
Cyclic Redundancy
Check (CRC) - CRCs are similar in concept to checksums, but they use polynomial
division to determine the value of the CRC, which is usually 16 or 32 bits in
length.The good thing about CRC is that it is very accurate. If a single bit is
incorrect, the CRC value will not match up. Both checksum and CRC are good for
preventing random errors in transmission but provide little protection from an
intentional attack on your data. Symmetric- and public-key encryption
techniques are much more secure.
All of these various processes
combine to provide you with the tools you need to ensure that the information
you send or receive over the Internet is secure. In fact, sending information
over a computer network is often much more secure than sending it any other
way. Phones, especially cordless phones, are susceptible to eavesdropping,
particularly by unscrupulous people with radio scanners. Traditional mail and
other physical mediums often pass through numerous hands on the way to their
destination, increasing the possibility of corruption. Understanding
encryption, and simply making sure that any sensitive information you send over
the Internet is secure (remember the "https" and padlock symbol),can
provide you with greater peace of mind.
NEXT COMING:::SMARTCARDS,ATM SECURITY
