Types of Encryption

diskThere are numerous kinds of encryption to protect electronic data. Using various algorithms, encryption supports numerous communication methodologies. Examined here are a few popular means of encryption used today.


This cryptographic algorithm, a federal information processing standard, is used within government for protecting data within non-classified environments. Designed to replace legacy encryption methods such as DES and 3DES, AES has been approved for use by “the Secretary of Commerce as the official federal governmental standard”, and the selection thereof has included “…the U.S. government, private industry, and academia” (Whitman & Mattord, 2005). Experts tout that to compromise AES security would take over 4 quintillion years to accomplish. How this encryption works is by converting a block of 128-bit text to 128-bit encrypted, otherwise known as cipher text, by using one of three key strengths: 128, 192, or 256-bit keys. The algorithm behaves in a different manner within each key size. So, “…the increasing key sizes not only offer a larger number of bits with which you can scramble the data, but also increase the complexity of the cipher algorithm” (Allman, 2002).

The algorithm is not truly symmetric in contrast to the predecessor, DES, and repeats it core in numerous periods depending on the key size. Known as rounds, these loop repetitions within the cipher “complete pre-round and post-round operations” (Allman, 2002).

A symmetric cipher – based form of encryption, Blowfish symmetric cipher is popular for protecting electronic documents, PDF’s, and compressed archives. Used within electronic transfer over the internet or locally on a workstation, Blowfish uses a pass phrase key for encryption and decryption of data. This is a 64-bit that both encrypts and decrypts at 64 bit chunks. Blowfish can be used to verify the sender of the message, “…or that the message is unaltered; however, you cannot prove these things to anyone else without revealing your key.” (McBride & Matthew, 2004).

A free form of encryption, Blowfish is unpatented and license-free. Used in numerous business applications and operating systems such as Linux as well as the popular TiVo DVR product, this type of symmetric cipher has not yet been cracked according to most cryptographers.

Digital Certificate

A mainstay in hypertext transfer security, the digital certificate is an electronic document that contains identification of an entity; such as a web page, by storing a key value about the identification of that entity. Often registered by a third party such as a digital certificate provider such as Verisign, known as a certificate authority, the certificate will provide a means of proving the identity of the entity, or site, to the requestor. According to PC Magazine, there are four general uses for digital certificates: secure (SSL & https) web connections, web client authentication, signing and encrypting email, and software publishing (PC Magazine, 1999).

The digital certificate contains a digital signature which uses the certificate for verification. The certificate contacts the certificate authority (CA) database, or repository, in which it is hosted: from that database the site is verified. Two such types of certificates are used today: PGP (Pretty Good Privacy) and X.509v3 from the Telecommunications Union (ITU-T).


The Secure Socket Layer was developed by Netscape to provide secure channels for browser communication over the internet. Within a client-server connection, the server controls the secure connection by sending a signal to the browser client that a secure connection is necessary. A public key would be sent by the client, and this has to match the public key found by the server, which sends a certificate for the client’s authentication. When verified by the client, the SSL connection is established.


McBride, M. (2004). Securing Communications and Files. Searcher. Vol. 12 Issue 5, p46.

Allman, S. (2002). Encryption and security: the Advanced Encryption Standard. How it Works.Vol. 47. P26

Pleas, K. (1999). Certificates, Keys, and Security. PC Magazine Vol. 18. Issue 8.