by Ed DeHart
For thousands of years mankind has desired and sought out secret and secure means of communication. This was oftentimes necessitated by war or other political emergencies. Today, military
and national security concerns are still of utmost importance. Internet-based commerce, however, has brought communications security to the forefront in a broader sense. Modern digital-based
encryption methods form the basis for the security that we often take for granted when making purchases or tending to banking tasks online. Although we currently enjoy very secure systems, there are
many incidents of intrusion and malicious hacking that make us think twice when sending sensitive
personal data across the Internet. Crimes such as identity theft are common and can cause significant suffering to the victim. The future may indeed hold better and more secure methods, maybe
even the ultimate security: a truly unbreakable method of encryption.
When information is transmitted, there always exists the possibility of interception by a party outside of the intended sender-receiver
domain. Although current networking technology provides means of
intrusion detection, it can never be known for sure if information has
been obtained and distributed to unintended receivers. Encryption, a
strategy to lessen this risk, seeks to make any intercepted or inappropriately obtained information unintelligible to the intercepting party.
The two classes of encryption are codes and ciphers. In this article
we will examine how encryption works to accomplish the greater
goal of information and communications security. In an overview
fashion, the classifications and basic mechanics of encryption will be
examined. Brief historical references will be made to demonstrate
how encryption has played a role in communications through the
years. Finally, a discussion of the possibilities that the future may hold
with regards to data encryption will be presented.
As with any pursuit of advancement in technology, there are
trade-offs that must be made, and data encryption is no exception.
One of the major tasks is to ensure that the algorithms or keys for
encryption and decryption remain unspoiled and secret to outsiders,
yet known to the intended users. Another task is to devise a scheme
that meets encryption needs and is practical. The system must not
be burdensome with regards to resources to the point of being inefficient. We will look at some basic methods of encryption that have
been employed for millennia, as well as modern means to meet the
current needs for advanced data security.
Means of Accomplishing the Task
Encryption methods are built upon the ideas of replacement and
scrambling, or mixing up a message so as to be unintelligible to any
intercepting party. This is by no means done in a haphazard manner.
The sender and receiver utilize methods and keys for encryption that
are known to both, but unknown to outside parties. The more complex the encryption process, the more difficult it is to break the
scheme. However, added complexity usually involves more lengthy
encryption and decryption processes.
Terms describing encryption are often misused and misunderstood. The following list contains some of the most common terms
with definitions [ 4, 10].
cipher a manner of encryption carried out at the symbol level
(i.e., letter or number) by transposition or substitution
ciphertext data or message encrypted with a cipher
cleartext unencrypted data or message
code a manner of encryption carried out on a group or block of
letters, numbers, or symbols
codeword a word, group, or block of symbols encrypted by
a coding scheme
cryptography the study or science of data encryption
encipher to encrypt a message with a cipher
encode process of encryption with the use of codes
encicode a message that has been encrypted by both coding
and cipher methods for additional security
encryption the process of making data secret by enciphering or
encoding or both
missive an unencrypted message
plaintext unencrypted data or message
The code and cipher are the two methods of encrypting data.
Encryption must be thought of as an umbrella term that covers both.
Likewise, decryption encompasses the processes of deciphering and
decoding. Furthermore, there are methods that involve both codes
and ciphers, and the terms encryption and decryption may apply to
these methods as well [ 10]. A term that frequently emerges in formal
writings of the history of encryption is missive. This simply refers to
an unencrypted message, and is synonymous with “plaintext,” or