Once an SSL connection is recognized, the server certificate in use can usually be scrutinized by looking at the assets of the page conveyed over the SSL connection. Certificates and keys are normally stored on the hard disk of the computer. Additionally to needing a password when the private key is used, it is typically also required to import or export keys and certificates. Some browsers also hold key and certificate storage on a secure external device (Using PKI, 2004). Certificates given to web servers and individuals are signed by a Certificate Authority. The signature on a certificate recognizes the particular Certificate Authority that issued a certificate. The Certificate Authority in turn has a certificate that connects its identity to its public key, so you can verify its uniqueness. A certificate authority issues a policy defining its practices so users of certificates issued by that Authority have a basis from which to make a trust judgment for transactions based on PKI (Using PKI, 2004).

Public-key cryptography facilitates the following tasks:

Encryption and decryption permit two communicating parties to disguise information they send to each other. The sender encrypts, or scrambles the information before sending it. The receiver decrypts, or unscrambles, the text after receiving it. While in transit, the encrypted information is jumbled to an intruder.

Tamper detection allows the receiver of information to verify that it has not been modified in transit. Any attempt to change data or substitute a false message for a legitimate one will be discovered.

Authentication allows the recipient of text to determine its origin and to confirm the sender's identity.

The first is plaintext which is the readable message or data that is fed into the algorithm as input. The second is encryption algorithm which performs various transformations on the plaintext. The third and fourth ingredients are the public and private key which is a pair of keys that have been selected so that if one is used for encryption, the other is used for decryption. The precise transformations performed by the encryption algorithm depend on the public or private key that is provided as input. The fifth ingredient is ciphertext which is the scrambled message produced as output. It depends on the plaintext and the key. The last ingredient is decryption algorithm which is when the algorithm accepts the ciphertext and the matching key and produces the original plaintext (Introduction to Public-Key Cryptography, 1998).
References

Introduction to Public-Key Cryptography. (1998). Retrieved April 8, 2010, from Web site:

http://docs.sun.com/source/816-6154-10/contents.htm

Public Key Certificate. (2010). Retrieved April 7, 2010, from Search Security Web site:

http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci497876,00.html

Public Key Directory. (2010). Retrieved April 9, 2010, from The Kumachan Website:

http://www.thekumachan.com/?p=1863

Using PKI. (2004). Retrieved April 9, 2010, from Dartmouth Computing Web site:

https://www.dartmouth.edu/~pkilab/pages/Using_PKI.html