My Birthday

Few days ago was my birthday. Stepping my live into a year older from the time i was born and a year young to the other starting point. I am completely at the age of two lowest singapore coins amount end with “0” (zero).

Thanks to my brothers(especially to my great bro S.K.H), sisters (especially Ifney) and my honey VGL, and dearest friends for the great birthday wishes sent through facebook wall feature or direct sms to me.

Thanks to dearest V.G.L for congrating me Happy Birthday 2 days before the actual day and the great present.

Thanks to my lovely roommates (S.W. and H.S.) for knocking my room door and presenting me a birthday cake with a brightly shining candle. Made a wish and blowed the candle. Nice. I am gonna missed it guys. Some more, it happened few hours after our discussion about the horrible taking turn to clean up the apartment. Holy Cow !

Thanks to my dearest friends who booked a karaoke room and presented me a birthday cake (another chance to blow the candle again) and the holy “Happy Birthday” song. It was scheduled until 11pm, but we ended singing far longer beyond that. That was memorable.

Thanks for being there. May all the wishes come true to both you and I.

Cheers,   Boleto

Birthday :: Getting Older,Younger or Both ?

Next month, November, is my birthday month. A month that is full of joy, happiness and etc….

Friends and relatives would send me greeting messages through my mobile, my social networking account as well as my personal email, saying “Happy Birthday”. Some greetings come with great wishes, some simply don’t. Well, it’s ok. At least they still remember my birthday and I really appreciate their efforts to send all those messages. Feeling happy during the day, especially while receiving all those greetings, is kind of a normal reaction. A group of friends would arrange for a surprise birthday dinner (party) which is usually accompanied by a birthday cake, singing the holy “Happy Birthday” anthem, lighting up the candle sometimes indicates how long we’ve been living in this world, making a wish and blowing the candle’s light off. Everyone will clap his/her hands making the surrounding area to become uproarious right after the light is off. Piecing and sharing the cake to everyone are the following actions. Wow…Great, what a perfect birthday ceremony.

One’s attributes, especially the age and or physical appearance in general, are changing from one stage to another one on the birthday. Some friends will strengthen this statement sometimes by telling jokes or fooling the birthday girl / boy about the holy attributes.  The attributes, however, are continuously changing over the time, not only on the birthday itself. It is just we seldom realize this little piece of fact. Anyway, it doesn’t make any difference whether we realize it.  See this, most of us will say, ‘well now you are one year older’. Wow, great statement which is very meaningful. It might imply that you are getting more mature in every aspect, or that you are getting better than what you were at the year before, or the other way round.

I am more interested to discuss about the statement ‘you are one year older now!’.  Human’s life starts from when he / she is born until he / she is dead. This process can be represented by a journey from one starting point to the final destination point. The length is how long we live in this world, this is unpredictable but i am sure if it is fixed. Theoretically speaking, the journey starts from the day and time a person was born on. And the journey uncontrollably and constantly moves towards the other end.

Let us discuss it in mathematical way. The length of a human’s life is denoted by L. The time a person is born is denoted by t1, and the time a person is dead is denoted by t2. So, L = t2 – t1. When the baby is 1 year old, he / she is 1 year away from the starting point (now t1 = t1 +1) and 1 year closer to the destination point (now L = L – 1). Therefore, when someone celebrates birthday, the person is both 1 year older and younger. Older in the sense of the time we have left the starting point (t1)  and younger in the sense of the time left to the destination point (L). See the graph below.

ageovertime

Even though the fact that we don’t know the time when a person reaches his / her destination point (t2), the simple calculation and the graph above tell perfectly the point i am trying to bring up.  So … until this point I guess I am clear about this.

Anyway, this is only my simple opinion, and you might have your own one. Do share with me !

Cryptanalysis

Cryptanalysis, the breaking of cryptography, base on the level of attacks, can be performed passively or actively. Passive attacker observes only the flow of the encrypted message (ciphertext) over the communication channel and tries to decrypt the ciphertext, while active attacker tampers with the ciphertext in order to change the meaning of plaintext. The purpose of attack usually is to determine the key or the plaintext that is used in a communication.

Common types of attack are :

Ciphertext-only attack

Attacker has only a ciphertext C.

Known-plaintext attack

Attacker has a plaintext M and the corresponding ciphertext C.

Chosen-plaintext attack

Attacker can obtain an arbitrary set of ciphertext C and its corresponding plaintext M of his own choosing.

Chosen-ciphertext attack

Attacker can obtain an arbitrary set of plaintext M from its corresponding ciphertext C of his own choosing.

Adaptive chosen-plaintext attack

This attack is similar to chosen-plaintext, but the attacker can choose the subsequent plaintext based on the information learned from the previous encryption process

Adaptive chosen-ciphertext attack

This attack is similar to chosen-plaintext, but the attacker can choose the subsequent plaintext based on the information learned from the previous encryption process.

Related key attack

Like a chosen-plaintext attack, the attacker can obtain the ciphertext using two different keys. The keys are unknown, but the relationship between the keys is usually known.

Substitution Ciphers

In this post, a simple explanation about “Substitution cipher” and the security of such a system are given.

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Substitution cipher is a very basic method of encryption which all plaintext contents are replaced with the ciphertext. If we assume that the original only has 26 characters, let say alphabet characters, a to z, regardless whether it is in capital letter, then the encryption function (E(M)) is defined as permutation of the 26 alphabet characters. See the following examples for the encryption and decryption function.

Encryption Function (E(M)):

encryption

Decrytpion Function (D(C)):

decryption

Using the encryption function above, the plaintext HELLO WORD is encrypted into the ciphertext CBHHL WLQG.

The security feature

The security of substitution cipher depends on the permutation of the 26 alphabet letters. The keys for encryption and decryption are determined by the permutation itself. The permutation is kept secretly and is only revealed to legitimate user of a system.

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Hope it helps !!

….along with a proud rabbit who looks down on the turtle….

and there the story goes
bout a rabbit who likes to boast
that he could achieve the uttermost

cuz the turtle is slow
well, that we already know
but he’s not willing to let go

and so the race start
the rabbit dash with all his heart
in a second he’s miles apart

ugly turtle can seem to do none
he tried as hard as everyone
yet he got so little done

but he ain’t lettin’ go
cuz he always know
that it’s not the end of the show

now that the rabbit feels tired and hot
he needs to stop and rest alot
so the ugly turtle gives his best shot

turtle dashing with no fear
morning is gone, afternoon is here
without realizing the finish line is near

finally the turtle makes it to the finish line
it’s the persistency that the rabbit couldn’t find
it’s the same thing that makes the ugly turtle shine

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Thanks to betty for initiating the dotted lines and idea, handy for the initiative, harta for the encouragement, Eddy for the title and Wolly for the completion.

Introduction to cryptosystem

Just wanna write something that is meaningful for learning purposes.

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Cryptology by the definition is the mathematics and the application of formulas and algorithms that underpin cryptography and cryptanalysis. Furthermore, it is the theory of data security and data integrity.

Cryptography as a branch of cryptology is the design of secure data and communication systems, while cryptoanalysis, the other branch, is the opposite, the breaking of cryptography.

Encryption is the basic tool in cryptography. Given a data, encryption will transform the data info a security protected data format which do not release any clue about the original data content. The process to reveal the original data content from the security protected data format is called by decryption.

Cryptography as defined as the design of secure data and communication systems has the following communication model.

Introduction to cryptosystem

Sender (A) sends the message (M) securely over a communication channel to the recipient (B).

To transfer the message securely, A will first encrypt the message plaintext (M) using the encryption function E(M). Encryption process will result a ciphertext (C). Then C will be transferred through the communication channel. Upon receiving C, B is required to decrypt C using a decryption function D(E(M)) in order to reveal the original message M.

C = E(M); D(C) = D(E(M)) = M, where E and D are encryption and decryption functions or algorithm respectively.

The security feature

Secure data and communication systems depends on, the important part, how strong the function or algorithm of the E and D. E and D often belong to a parameterized family of functions which usually associated with a certain key, encryption and decryption keys respectively. The security is based on the protection the specific keys. Nowadays, calculating key space (possible combination of keys) is trivial, so the keyspace must be large enough to prevent exhaustive search.

Key Distinction

There are 2 distinct cryptosystems based on the encryption and decryption key, symmetric and asymmetric cryptosystems. Symmetric cryptosystems uses identical key for both encryption and decryption key while asymmetric cryptosystems uses different keys. Since symmetric cryptosystems uses the same key, it is easy to obtain from each other, while asymmetric is hard to obtain to each other.

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That’s all for the current post. Hope it helps.
Cheers

Right or Wrong

Right or Wrong ….

I have been thinking about these two words, “Right” and “Wrong”, since the past few years. I find it very interesting because the gap of “right” and “wrong” is as thin as a membran in term of thickness. Or in other words, it is almost invisible, almost unperceivable. But, the difference is always there, just the matter of how sensitive our mind to digest the situation and how meticulous our eyes to look into it.

The word “right” based on http://www.dictionary. com has several meanings, such as “in accordance with what is good, proper or just : right conduct”, “in conformity with fact, reason, truth, or some standard or principle”, “correct in judgement, opinion, or action”, and etc…. while the word “wrong” has several meaning as well, but all the meanings are in negation with the word “right”. “not in accordance with what is morally right or good”, “deviating from the truth or fact”, “not correct in action, judgement, opinion, method”, and etc…..

Is there anything that is definitely “right” or definitely “wrong”?

The following examples help me to understand those terms better.

First, Hittler believed that all his actions in the past were right. While most of the other people in the world untill today still believe that those are wrong. Were all his actions wrong? You might say “yes, it was” according to the definition given above and the humanity point of view. Or you might also say “no, it was not” if you are thinking from the other point of view based on the reasons why he did all his actions.

Second, Robin Hood and all his followers believed on the thinking that what he is doing is right, He stole from the riches, who mostly become rich illegally, and gave it to the poors. Such a kind hearted man, helping the poors by putting himself in the border line. Everybody praised on him, such a big hero. However, the law has another opinion that what he did, stealing, is definitely wrong.

Right or wrong is only a perspective. Actions, rules, regulations, and this very short writing are both right and wrong. It depends on which perspective we look into a situation from. Make up your mind and eagle view everything we are facing with for a better understanding.

Cheers