One of the common question in Information Technology World is: What is the relation within Public/Private key and Encryption / Decryption? How do we use public / private key to encrypt/ decrypt? How do we use public/private key for digital signature?
Real world applications for Digital Certificates
So far we have briefly illustrated the theory behind the Digital Certificate and its role in the deliverance of PKI. The following pages now look at the practicalities of using a Digital Certificate, where to find them on your PC, and what they actually look like.
Using Digital Certificates to deliver the 5 primary security functions
Identification / Authentication:
The CA attests to the identity of the Certificate applicant when it signs the Digital Certificate.
The Public Key within the Digital Certificate is used to encrypt data to ensure that only the intended recipient can decrypt and read it.
By Digitally Signing the message or data, the recipient has a means of identifying any tampering made on the signed message or data.
A signed message proves origin, as only the sender has access to the Private Key used to sign the data.
Access Control may be achieved through use of the Digital Certificate for identification (and hence the replacement of passwords etc). Additionally, as data can be encrypted for specific individuals, we can ensure that only the intended individuals gain access to the information within the encrypted data.