security + robustness

:: In The Name of Allah, Most Gracious, Most Merciful ::

There are two important aspect of information hiding system; security and robustness :

security = inability of an eavesdropper to detect the hidden message

robustness = the amount of distortion that the digital cover can withstand before the hidden message is destroyed

[Qutayri, 2004]

robustness

:: In The Name of Allah, Most Gracious, Most Merciful ::

they define it as…

We define steganographic secrecy in terms of computational indistinguishability, and we define steganographicrobustness, which deals with the case of active wardens (ones that cross out innocent-looking sentences or modify the messages just to prevent secrets from going through). Our main result is a positive one: secret
and robust steganographic protocols … [Hopper, 2002]

key size [cryptography]

mr wiki said …

In cryptography, key size or key length is the size measured in bits of the key used in a cryptographic algorithm (such as a cipher).

An algorithm’s key length is distinct from its cryptographic security, which is a logarithmic measure of the fastest known computational attack on the algorithm, also measured in bits. The security of an algorithm cannot exceed its key length (since any algorithm can be cracked by brute force), but it can be smaller.

For example, Triple DES has a key size of 168 bits but provides at most 112 bits of security, since an attack of complexity 2112 is known. This property of Triple DES is not a weakness provided 112 bits of security is sufficient for an application.

Most symmetric-key algorithms in common use are designed to have security equal to their key length. No asymmetric-key algorithms with this property are known; elliptic curve cryptography comes the closest with an effective security of roughly half its key length.

terms 2 : digital text

:: In The Name of Allah, Most Gracious, Most Merciful ::

Mr.wiki said :

In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language.

Examples of characters include letters, numerical digits, and common punctuation marks (such as ‘.’ or ‘-’). The concept also includes control characters, which do not correspond to symbols in a particular natural language, but rather to other bits of information used to process text in one or more languages. Examples of control characters include carriage return or tab, as well as instructions to printers or other devices that display or otherwise process text.

Characters are typically combined into strings.

and ASCII is ..

The American Standard Code for Information Interchange (acronym: ASCII; pronounced /ˈæski/, ASS-kee)^[1] is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character-encoding schemes are based on ASCII, though they support many more characters than did ASCII.

US-ASCII is the IANA preferred charset name for ASCII.

term 1 : unicode

:: In The Name of Allah, Most Gracious, Most Merciful ::

excuse me miss, what is it Unicode?

Unicode is a computing industry standard for the consistent representation and manipulation of text expressed in most of the world’s writing systems.

source: wikipedia

woho! Are there any simple english? huhu~ and through my searching I found out a perfect explanation. Which the experts talks about it.

Unicode provides a unique number for every character,
no matter what the platform,
no matter what the program,
no matter what the language.

-unicode.org-

In deep thinking, we can see where the contribution of something is inherit from an issue that arise. The same thing about the Unicode. Unicode provides a unique numbers for every character and solving the encoding conflict in the text presentation. (my note : this will be by homework in term 2 : text presentation in computer )

miss, where is my character?

Unicode Standard provide a code chart for specific data. In our case here we will refer the middle eastern script column –> Arabic presentation Form A.

wait.. miss. there is three Arabic presentation. why you choose Form A?

because java eclipse IDE support only for this type of unicode for Arabic presentation

this is an important line:

For each character defined in Unicode you will find an assigned code point: a hexadecimal number that is used to represent that character in computer data.

-unicode.org-

ok, for a time being.. those two links of reference is much enough for me to dig the gold in those info.

this entry will always be updated. As it is growing the thought !