Terry Addison

IAAS483

DAVENPORT UNIVERSITY ONLINE

August 9, 2011

Dan Parrell, PhD

Certificate of Authorship: By submitting this assignment I hereby certify that I am the author of this assignment. I understand that all coursework is governed by the University Academic Integrity Statement outlined in the DU catalog. I have not consulted or collaborated with anyone else outside of the Davenport University Online classroom environment. I understand that I may use reference material, but my submission should reflect my individual effort and any material utilized outside of the course textbook must be properly referenced and documented using APA format.
Digital Signatures
A digital signature is a way to ensure that an electronic document is authentic. Digital signatures rely on certain types of encryption to ensure authentication. There are several ways to authenticate a person or information on a computer:
Digital certificates - 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 essentially a bit of information that says the Web server is trusted by an independent source known as a Certificate Authority. The Certificate Authority acts as the middleman that both computers trust. It confirms that each computer is in fact who they say they are and then provides the public keys of each computer to the other.
Private key encryption -Private key means that 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 the other computer. Private key requires that you know which computers will talk to each other and install the key on each one.
Password - The use of a user name and password provide 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 password do not match, then you are not allowed further access.
CRC (Cyclic Redundancy Check) - 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. transmission, but provide little protection from an intentional attack on your data. The encryption techniques below are much more secure.
Public key encryption - 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 it's own private key.
How It Works
Assume you were going to send the draft of a contract to your lawyer in another town. You want to give your lawyer the assurance that it was unchanged from what you sent and that it is really from you.

1. You could copy and paste the contract into an email note.

2. Using unique software, your obtain a message hash of the contract.

3. Make use of the private key that you obtained from a public-private key authority to encrypt the hash

4. The encrypted hash becomes your digital signature of the message.

Your lawyer receives the message makes a hash of the received message. He then uses your public key to decrypt the message hash. The hashes match and everything is copasetic.

References

Digital signature (electronic signature). (n.d.). Retrieved August 9, 2011, from http://searchsecurity.techtarget.com/definition/digital-signature

Digital Signatures Featured Articles. ( n.d.). Retrieved August 9, 2011, from http://www.ehow.com/digital-signatures/