SCIENTIFIC WORKS COMPUTER NETWORK SECURITY SYSTEMS
CHAPTER. I INTRODUCTION
Not all information is accessible by everyone. Information is something very valuable if the information is concerned about aspects of business decisions, security or public interest. limited information needs to be maintained the authenticity, availability and secret when the information will be sent eligible. There are different types of information security techniques such as the technique of "Steganography".
Steganography is a Greek wrong Steganos meaning "hidden or concealed" and graphein meaning "to write" so steganography means "writing (writing) veiled". Steganography techniques has been used for more than 2500 years. Steganography is the science and art of hiding (embedded) information by inserting messages in other messages. The purpose of steganography is hiding or hiding the existence of a hidden message or an information. Besides Steganography can also be used to authenticate against a work as the utilization of watermarking.
Steganography is divided into several times, the ancient, Renaissance, and modern.
• Ancient steganography
Ancient Steganography has been known since the time of Herodotus (485-582 BC). Then Pliny the Elder with his invisible ink.
• steganography Renaissance Renaissance
Steganography was started in 1518 by Johannes Trithemius cipher who find steganography on each letter represents a word. Other figures are Giovanni Battista Porta (1535-1615) using egg shells as a cover object and written messages can be read after the shell is removed.
• Modern steganography Modern
steganography by Simmons in 1983 in the USA.
Some examples of the use of steganography in the past are:
• In the year 480 BC, a Greek man that Demaratus policy sends a message to Sparta that contains warnings about the attack Xerxes delayed. The technique used is to use a table that has sculpted then given a layer of wax to cover the message, so the message can be delivered in a table without suspicion by the guards.
• Use inks that are not seen in other posts.
To insert a message that will be sent to use several types of media. This media type that would later be used as a carrier of a secret message such as audio files.
Unlike cryptography, where the character of the message is converted / encrypted into other forms that are not meaningful, the steganographic message itself retained only in the delivery obscured / hidden in various ways. , Then in the first steganography should do is find a steganalis stego object first, because it is a secret message hidden (not visible) in another medium (cover).
• Research Objectives
The purpose of choosing a title and make this paper was to gain knowledge about the techniques used to protect confidential information from unauthorized person other than cryptography.
• Research Methods
The method used in this paper are completed by observation from a variety of sources such as books and the Internet.
CHAPTER. II THEORETICAL
There is a wide range of media that can be used to insert information or messages to be sent. In theory, all the common files on the computer can be used as a medium, such as an image file format JPG, GIF, BMP, or in the MP3 music, or even in a movie with a WAV or AVI format.
The medium used is usually a different media with confidential information carrier, which is where the function of steganography technique that is as camouflage technique using a different media so that the confidential information in the initial medium is not seen clearly [Waheed, 2000].
Steganography technique has been widely used in warfare strategy and delivery cipher since time immemorial. In World War II, steganography techniques commonly used by the German army in sending
secret messages to or from Germany [Simmons., 1983].
As a general function, steganography is used to give a special stamp in a work created in the electronic media as identification [Johnson, 2006].
Steganographic data hiding scheme in general is as follows:
• In the above data or information that you want kept hidden in a container (cover) with a particular steganography algorithms (eg LSB). To increase the level of data security, may be the key, so as not everyone is able to express the data stored in a file container (cover). The end result of the process of data storage is a stego file (stego data / stego file).
• The process of disclosure stego file illustrated in the following figure:
Stego file is extracted after the enter key is required. This is the extraction of information or data that is stored along with the file stego. In most steganographic technique, extracting the message will not return the exact same stego file with a file container (cover) while the message is saved, it is because when the message store is not done recording the initial conditions of the beam container used to store messages. Thus if wanted removal message from the stego file to do them is by changing the value of the pixel at random from pixel - pixel messages are stored in a file.
CHAPTER. III DISCUSSION
a. Steganalisis and Stegosystem
Steganalisis can be defined as the art and science of detecting hidden information. Stegosystem essentially contains the attacks carried out against a system steganography. There are two types of attackers that passive attacks where the attacker can simply cut the data and active attacks where the attacker can manipulate the data.
Steganography poorer used also to perform criminal acts. Steganography also allegedly used by terrorists to carry out the action. With steganography maps, goals, and action plans disguised terrorist sites on the mailing list of sports and porn sites. Thus the advantages of steganography is unfortunate when used for evil purposes. Other crimes that may be facilitated by steganography ie for gambling, scams, viruses, and others.
There are several terms in steganography, namely:
• Carrier file: a file that contains a secret message
• Stego-medium: medium used to carry secret messages or insert a secret message.
• Redundant bits: some of the information contained in the file which if removed will not menimbulakn significant damage (to the senses)
• Payload: information to be hidden
The word steganography is often referred to in the community together with the word cryptography after the bombing of the World Trade Center in the U.S., where U.S. officials claimed that the terrorists hiding messages of terror activities in various pornographic images, MP3 files and a particular web site. Da Vinci Code novel also helped popularize steganography and cryptography
b. Audio Steganography Method
There are several ways to apply steganographic on the audio file are:
• Low Bit coding
This method is commonly used in digital steganography technique that is replacing the LSB input each sampling the encoded data. With this method the profit is a measure of the relative message, but the impact on audio quality results with much less noise.
• Phase coding
The second method used is the reverse phase of the input signal. The theory used is by substituting the initial phase of each initial segment with a phase that has been designed as such and represent a hidden message. Phase of each initial segment is such that each segment still has a relationship that led to the voice quality is maintained. This technique produces output that is far better than the first method but compensated with a complexity of realization.
• Spread Spectrum
The third method is the spread spectrum. With this method the message is encoded and distributed to every possible frequency spectrum. So it will be very difficult for those who would try to break it unless he has access to the data or to reconstruct random signals that are used to spread the message on frequency range.
• Echo Hiding
The latter method is often used to hide a message via echo technique. Techniques to disguise the message in the form echo signal. Then with a hidden message in the echo three parameters, namely the initial amplitude, decreased levels of attenuation and offset. With the offset of the echo and echo the original signal will be mixed with the original signal, because the human auditory system that does not distinguish between the original signal and the echo.
c. Steganography with Audio File Media
MPEG (Moving Picture Expert Group) -1 Audio layer III or better known as MP3, is one of the digital audio encoding and also an audio compression format which has the properties of "lose". The term in question is a compression eliminates audio into mp3 format eliminates those aspects that are not significant in human hearing to reduce the size of the audio.
MP3 is a development of previous technologies so that the smaller size can produce quality equivalent to CD quality. Specifications of the layers as follows:
• Layer 1: The best at 384 kbit / s
• Layer 2: best at 256 ... 384 kbit / s, very good at 224 ... 256 kbit /, both at 192 ... 224 kbit / s
• Layer 3: The best at 224 ... 320 kbit / s, very good at 192 ... 224 kbit / s, good at 128 ... 192 kbit / s
Popularity of mp3 which until now has not competed due to several things. Mp3 can be distributed easily and at almost no cost., Even though the patents have owned and deployment mp3 mp3 should be free of charge. However, the patent owner of the mp3 has given a statement that the use mp3 for personal purposes free of charge. Another advantage is the ease of access to mp3, where a lot of software that can produce mp3 files from CDs and mp3 files that are being ubiquitos (cosmopolitan).
In these discussions will be used for software MP3Stego hide message into an MP3 file. This program is used only to prove that steganography in MP3 can be done. As mentioned above, MP3Stego can be used for steganography. The workings of the program on the basis of audio compression techniques from WAV to MP3. As already known, the MP3 is a compression that is "remove" the data are not significant to human hearing, and therefore use the advantage that this program does not eliminate all redundant data, but was replaced with a message that will be included.
In general, the coding and compression of MP3 divided into two cycles of iteration is in the form of cycle iteration cycle for ratification and beyond iteration cycle for controlling distortion and noise. Here's a chart image compression MP3 namely:
MP3Stego enter data during the compression process to the process in the iteration cycle. The process of hiding a message in outline is compressed and encrypted message and the last bit hidden in a series of MP3. After experiencing compression, and the message is encrypted to guarantee keamananya. As discussed above, the steganographic message is considered to be unknown to the security of the message should be security measures, including encryption. 3DES encryption used is an already proven its reliability, so that even if their existence is known contents will remain safe.
Then proceed with the deployment process in a series of messages encrypted bit MP3. The process of this was the process that the harder the whole process. First, this process happens in the iteration cycle, in this iteration cycle occurs quantization of data from the input signal corresponding to the model of the human auditory system, and collect the data until it reaches the right size so that it can be encoded. While other cycles ensure data meets specification model the human auditory system. Then to insert a message, be parity bits for Huffman code and scale factor. Of course, with the replacement of this parity must be adapted, which is the final stage of the iteration cycle. The spread of data is done at random, based on SHA-1.
MP3Stego flawed because the software is only a free program that has not been perfected. One of the MP3Stego to accommodate messages are large because of the large frame is determined MP3 where each frame can only accommodate 1 bit only. The file specification must be met as a carrier file is in WAV format, 44100Hz, 16 bit, PCM, and mono. If it does not meet the specifications of the process of inserting a message will fail. And if the MP3 compression results in the form of mono it will arouse suspicion.
• Insert Personal Files In File Photo
The steps are:
• Prepare and file to be pasted as an image file to insert media personal files. Store in a single folder. Personal files are saved in. Txt and image files in the format. Jpg.
• Then add the personal files on the "new RAR archives" (pesan.rar).
So there are 3 files in this folde C: \ secret
• Open "command prompt or cmd".
• Navigate to the folder C: \ secret
• Type copy / b twiti.jpg + rahasia.rar twiti_hid.jpg
twiti.jpg is the origin of the image file, rahasia.rar file to be inserted while twiti_hid.jpg is a file that contains both files.
So now rahasia.rar file (rahasia.txt file in the "zip" right) has been successfully twiti_hid.jpg paste on file. When the file is opened twiti_hid.jpg will not arise suspicion. As the picture below:
If you want to get the file rahasia.txt back of the picture above, we have to do a command like this:
After that will appear twiti_hid.rar file. Extract the file then you will see the file rahasia.txt
• Insert Personal Files In MP3 Files
The steps are:
1). Prepare a personal file and the file will be inserted. Wav WAV format specifications, 44100Hz, 16 bit, PCM, and mono if not then the insertion will fail. Here I use the file secret.txt LoopyMusic.wav and personal files. Save the file into the same folder with the software MP3Stego (sat in the directory). This process will be done at the command prompt.
2). Then we start to encode files into LoopyMusic.mp3 LoopyMusic.wav. Type the encode-E pesan.txt rx.wav rx.mp3. Then it will appear a statement asking for a secret word that will be used in the encryption process and spread the message and also asked confirm / retype the secret word. Here is an image of the encoding process, the secret word used is "mecha":
There are several options in the encoding process, namely:
3). Then from the file LoopyMusic.mp3 we will try to retrieve the hidden before. Type the decode-X rx.mp3. Then the program will ask for the secret word that is used during the compression process beforehand. Just like that the program will require typing / confirm the secret word. Then the file will be generated in PCM format and LoopyMusic.mp3.txt. Here is a picture of the decoding process, namely:
Just as the process of encoding, the decoding process there are various options, namely:
The files contained in MP3Stego namely:
Then the file LoopyMusic.mp3.txt have the following contents:
Using MP3. It seems clear that the file generated with
If the decoding process we enter the secret word is wrong then the execution is still being done but in the end will display an error message by the program,
CHAPTER. IV Conclusion
From the above couple of conclusions can be drawn as follows:
• Steganography is a method to hide a message in a message either in the form of images, sounds, and files that contain text without showing characteristic tangible or visible changes in the quality and structure of the original file so that other people do not realize that there was something in the message.
• The advantage of steganography techniques compared with cryptographic techniques, namely the presence of steganography to hide messages can not be detected easily because of hidden messages in such a manner as not to arouse suspicion. While cryptography to hide the existence of the information clearly known.
• Files that have undergone compression by using message inserted MP3Stegos can not be enforced just like the MP3 file. If the file is cut it will produce a sound that bad.
• If the encryption process using a secret word will generate false error messages from the program. So without a word remains safe secret message can not be accessed by others.
• File to be inserted should not be too long, a maximum of 14 964 bits of data. If you exceed the maximum limit of the encoding process will error.
• Use MP3Stego steganography tool proved to have good results. This proves that audio steganography to do with the security of the data using 3DES encryption and data dissemination randomized used principle SHA-1 which have both been tested toughness. The messages will be stored safely inaccessible to the people who do not have a secret word that is used. Mp3 of the compressed file can not be treated the same as an mp3 file normally, like a cut. In addition error handling of the program is adequate so that the program can be used with guaranteed security.
Due to the limited capabilities of the compiler that there are many flaws in this paper that expects me your comments and suggestions for the readers. The work can be developed further because there are still some things that can still be deepened for those who want development