Define one type of cryptography and describe the security features.

Asymmetric Cryptography: Digital Signatures Most of the time when we mention cryptography, or put asymmetric in front of it we are met with just plain blank stares. In the following paragraphs I will attempt to explain what it is, and give examples on its use. First an explanation of Public Key Infrastructure, or PKI. A cryptographic system uses two keys, a public key known to everyone and a private key, the private key has full control to the key owner, and has to keep in secured environment. A unique feature to the public key system is that the public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them. Moreover, it is virtually impossible to distinguish the private key if you know the public key. When employee A wants to send a secure message to employee B, you use the employee B’s public key to encrypt the message. Employee B, then uses their private key to decrypt it. Public Key cryptography, is also called asymmetric encryption because it uses two keys instead of one key (symmetric encryption). Next, for my example of a process that utilizes asymmetric cryptography, is Digital Signatures. I will be using employee’s A and B as my subjects to explain the digital signature process. First, from employee A’s point of view the signing process is simple. This is because few steps are enacted, while signing process is started. While employee A, digitally signs the documents, they need to obtain a Private and Public Key, a one-time process. This is accomplished when the user registered for the secured signing process. In addition, the Private Key will not be shared, and is only used for employee A’s signed documents. The Public key that is generated, is available to all parties, to validate the digital signature. When we digitally sign a document, we create a digital signature. The signature is a unique documents hash that represents the document created, using a math formula such as SHA-1. This hash result and the users digital certificate, includes the users Public Key and are mixed into a digital signature. This is done by using the users Private Key to encrypt the document hash. The resulting signature is unique to both the document and the user. With this information, the digital signature is embedded to the document. Joe would send the signed document to Jane. Jane uses Joe’s public key (which is included in the signature within the Digital Certificate) to authenticate Joe’s signature and to ensure the document was not altered after it was signed. Upon receipt of the document Jane checks to ensure document has not been altered:
Validation process starts.
Decrypt Joe’s digital signature with his Public Key and receive the sent document.
Compare Joe’s document hash with Janes
Jane calculates the document hash of the received document and compares it with the hash document in the digital signature. If both hashes are the same, the signed document has not been altered. The process is complete, the material covered herein is an example asymmetric cryptography that is used around the world, to digitally sign and protect documents.

Reference
OCC. 1999. Digital Signatures with Public Key Cryptography. Retrieved from http://www.occ.gov/news-issuances/bulletins/1999/bulletin-1999-20a.pdf
Rouse, M. November 2014. Digital Signature. Retrieved from http://searchsecurity.techtarget.com/definition/digital-signature