The very basic of Public Key Infrastructure technology is the science of Cryptography. Cryptography is a derivative of the Greek word, kryptos which means to hide or hidden. Cryptography is the science of using technology to hide data. When cryptography hides data to transmit over the Internet in secret or hidden form, the data is referred to as encrypted.
Encryption is the process that codes text or data from its original form and then transmits it over the Internet. Decryption is the process of receiving encrypted information and translating it back into its true form. Both encryption and decryption are the primary tools used in Cryptography.
When data is encrypted, the resulting form is called ciphertext. Using encryption and decryption ensures that when someone transmits sensitive information over the Internet, the original message or data will not be easily recognized. To decrypt the message, a decryption key is needed.
There is a great need for PKI as the way people use and transmit data is changing. Wireless technology is also increasing the need for secure systems and methods that will ensure absolute privacy when online.
In Cryptography and with Public Key Infrastructures, the process works by utilizing a private and public key. The encryption key is actually a mathematical algorithm. The more complex the algorithm, the more secure the key and the encryption in turn is harder to break.
One of the most popular forms of an encryption algorithm is RSA. RSA derives its name from the first initial of the last name of its three founders, Ron Rivest, Adi Shamir, and Leonard Adelman. The RSA algorithm is widely used and is included in both Microsoft and Netscape’s browsers.
The algorithm multiplies two prime numbers and then computes a series of mathematical operations and concludes with two final numbers. One of those numbers will be the private key and the other will be the public key. The private key belongs to the owner and is never transmitted across the Internet. A private key is kept secure with the owner.
The public key will be transmitted across the Internet and may be accessed by someone looking for it. The private key is used to decrypt encoded messages. Also, your public key information will be stored or included in your digital certificate.
Here is some information that will help you understand which key is needed for each function. If you are going to send an encrypted message to someone, you will need the recipient’s public key. If you are going to send an encrypted signature in your message, you will use your private key.
If you are going to decrypt a message that someone has sent to you encrypted, you will use your private key. If you are going to decrypt a signature that has been encrypted and you want to ensure that the sender is the authentic author, you will use the sender’s public key to decrypt the signature. Cryptography is the foundation that the rest of the Public Key Infrastructure is built upon.