History of Encryption
Encryption has been used by people in all situations such as in
military, corporate and personal information. The history
of encryption goes way back to when languages were first used. In battles and wars, the most important
thing was secrecy of planned manoeuvres. As well as for military uses, people
who want to hide important information from the public have
used encryption.
The oldest records of encryption or ciphers go back to more
than four thousands years. The first ciphers date back to the
early Egyptian times when hieroglyphics were carved in stone.
Ancient Babylonians also used intaglio (a collage of
images) to
differentiate traders.
In ancient Greek days Spartan generals wrote their messages on a narrow strip of
parchment wrapped around a thin cylinder. When the
parchment was unwound the message appeared as a nonsense
sequence of letters and could only be read by wrapping the
parchment around another cylinder of the same size. During the
fifth century BC, messages were sent tattooed onto the scalp of trusted
slaves. With the hair grown back, there was no indication that
a message was being carried at all. This sort of method
continued to be used until as recently as WWI, when agents were
sent across enemy lines with messages written onto their skin
in invisible ink.
A more
developed and systematic cipher was Julius Caesar’s method. of
substituting alphabets by a certain rule. More
sophisticated methods have since been developed since the 18th century.
While the old methods substituted or transposed words,
new ones totally change the data from text to other
formats such as hiding the message within a musical score. During the
Second World War, American armies used Navajo
soldiers to translate orders back and forth.
Today digital
encryption converts text to binary
data and a key, which is crucial for encryption, has been
developed to more complex.
In the early 1970's, the Data Encryption Standard algorithm
(DES) was introduced which uses a 56-bit key to encrypt and
decrypt information. DES splits each message into blocks and
then encodes each block one at a time. DES was adopted as an
approved algorithm for US Federal use but is no longer
considered adequately secure because a 56 bit key can be broken
by brute force (trying every possible key) in a relatively
short time (the exact time depends on the speed of the computer
used to try all the keys).
Hacking a DES encryption, as with any encryption method,
depends on the hacker already knowing one of two things...
either what algorithm is used or the key to unlock it. Without
either of these hacking DES is virtually impossible.
DES has since been superseded by the
Advanced Encryption Standard (AES), using the Rijndael
algorithm. AES operates with 128, 192 or 256 bit keys. These
are considered long enough to be safe for the foreseeable
future as they would take millions of millions of years to
break on the fastest computers presently available.
Recent encryptions have up to 256 bits of special keys so even
a supercomputer would be slow in trying all the possible
combinations. This of course ensures the security of data.
Encryption Key
A key is a long sequence of bits used for encryption/decryption
algorithms. Such as the following 40-bit key:
01001010 01100001 10001110 10011100 01110101
The encryption algorithm converts the original message
mathematically based on the key to create an encrypted message.
The decryption algorithm restores an encrypted message to its
original form.
Encryption on the Internet
The Secure Sockets Layer (SSL) is used for secure transactions
like ecommerce and banking using a key for encryption and a
different key for decryption. Because SSL encryption depends so
heavily on keys, the effectiveness or strength of SSL
encryption depends on key length (number of bits in a key). To
decode an SSL communication, one only needs the correct
decoding key.
In cryptography, a common decoding technique is brute-force
decryption using a computer try every possible key combination
one by one. 2-bit encryption, for example, involves four
possible key values.
Compared to 40-bit encryption, 128-bit encryption offers 88
additional bits of key length which provides
309,485,009,821,345,068,724,781,056 possible combinations
required for a brute-force crack.
Security experts estimate that to crack an 128-bit encryption
will require the computer resources of NASA and plenty of time.
- Image Encryption
- HTML encryption
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