Page 245 - DCAP403_Operating System

Operating System

Notes 12.12 Enterprise Authentication using Digital Certifi cates

When one connects to a secure web server such as https://www.Amazom.com and request that
server to authenticate itself, it has to so complex process involving public keys, private keys and
a digital certificate (also known as electronic credentials or digital IDS). They allow verifi cation of

the claim that a given public key does in fact belong to a given individual or entity. In other words

the digital certificate tells you that an independent third party has agreed that the server belongs

to the company it claims to belong to. A valid certificate means that you can have confi dence that
you are sending information to the right place.
12.13 Summary

Encryption is essentially the process of encoding – or hiding – the information you send across
the internet in a way that it can only be read by the person or website it is meant for. There are
various ways this is handled on the net.

There are two primary approaches to encryption: symmetric and public-key. Symmetric
encryption is the most common type of encryption and uses the same key for encoding and
decoding data. This key is known as a session key. Public-key encryption uses two different keys,
a public key and a private key. One key encodes the message and the other decodes it. The public
key is widely distributed while the private key is secret.

12.14 Keywords

Decryption: Decryption is the reverse process of converting encoded data to its original
un-encoded form, plaintext.

Digital signatures: A message signed with a sender’s private key can be verified by anyone
who has access to the sender’s public key, thereby proving that the sender signed it and that the
message has not been tampered with. This is used to ensure authenticity.

Encryption: Encryption is a process of coding information which could either be a file or mail
message in into cipher text a form unreadable without a decoding key in order to prevent anyone
except the intended recipient from reading that data.

12.15 Self Assessment

Choose the appropriate answers:
1. SSL stands for
(a) Secure Service Layer
(b) Secure Socket Layer

(c) Source Service Layer
(d) Secure Service Link
2. MAC stands for
(a) Message Authentication Code
(b) Message Authentication Course

(c) Message Authorization Code
(d) Message Activity Code

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