Cryptography System

  • Cryptography is a practice of creating and using encryption system
  • Cryptographic system is a method of hiding data so that only certain people can view
  • Plain text is the original data
  • Ciphertext is the protected data or the encrypted text
  • Encryption is the process or procedure to convert plain text to ciphertext
  • Decryption is the procedure of converting ciphertext to plain text
  • Cryptographic system consist of algorithm + key + key management facilities

2 basic type of cryptographic system

Symmetric

  • Have only one key – private key
  • use the same key to encrypt and decrypt

Asymmetric

  • Have 2 key
  • Public and private

What is ORB interface?

ORB interface is the one that provides access to every ORB service, except:

  • Client invocation (through Stubs or DII)
  • Object activation and call (through object adapter, typically POA)

The services include:

  • Access to Initial Service (Naming Service, Trader Service, Root POA and others)
  • Access to the IFR and construction of DII invocations
  • Object reference operations:
  • Conversion of Object references between Session and Stringifield format
  • Conversion of URL format corbaloc and corbaname object references to invokable references
  • Creation of duplicate object references
  • Releasing storage for object references
  • Policy operation including create_policy
  • valuetype factory operations
  • Thread related operations
  • incl work_pending and perform_work

What is ORB?

ORB is Object Request Broker.

It is a middleware that uses CORBA specification. It take care of all the details involve in routing a request from client to object, and routing response to its destination.

ORB is the custodian of the Interface Repository (IFR), an OMG standardized distributed database containing IDL interface definition.

On the client side:

  • ORB provide interface definition from the IFR
  • Construct invocations for use with the Dynamic Invocation Interface (DII),
  • Convert Object References between session and stringifield format
  • Convert URL-format corbaloc and corbaname object references to session references.

On the server side:

  • Same as above process. Plus,
  • ORB deactivates inactive objects.
  • Re-activates  object whenever request come in.
  • Activate and De-activates in the way that uses resources best.

ORB, wow!

Centralized versus Distributed System

Note: Tomorrow Exam.

Centralized

  • Have non autonomous component
  • Often built using homogeneous technology
  • Multiple users share the resources of a centralized system at all time
  • Have single point of control and failure

Distributed

  • Have autonomous components
  • May be built using heterogeneous technology
  • Distributed system components may be used exclusively
  • Executed in concurrent process
  • Multiple point of failure

Simply said, distributed system is better that centralized system should there be enough resources involved.

Centralized utilized the same resources for multiple user. An example would be Database system where multiple user access the same database on the same server. This also mean that the database have the server as the only point of control, thus translate to single point of failure.  It is either it work, or not.

In distributed system, it have autonomous components where they posses full control over their part all the time. There is also no master components that have total control over the system. Every component is on their own. It define an interfaces to communicate with each other.

Heterogeneous technology means the ability to integrate components on legacy system with newly written program on newer system. They’re able to integrate and communicate even though have different programming language even. Usually the source of the components is compiled into heterogeneous machine code.

Components also can be used (or is used) exclusively by only one user. Looks like disadvantage, but this is the advantages of distributed system where a shared component might get overloaded by too many user or too many request. More so that components can be located so they’re local to the users and other components it may interact with. This improve overall performance.

The components create new thread whenever they start to perform a service for a user or another components. That way the components is always open for another service. Also it have multiple point of failure. It is design to be like that so if one components down, the other component that is not related to it, still available for a service.

Clearly distributed system has an advantage over the centralized system. With all the autonomous, heterogeneous, multi threading and multiple point of failure, it sure have lots of advantages.

I Start A Web Hosting Business

After about one year (I think) I am thinking of more ways to get more income. I finally come to conclusion that selling web hosting is kind of profitable too. Also with low start up capital.

I choose to name it as Simply Hosting. Partly because of the domain name available is simplyhosting.biz. Haha :) I know… Crazy right… Just to pick business name from the available domain name. But that is the trend now. You ought to have business name that is the same as your url. If not, not cool man!

Anyway you all can visit my web hosting site here: http://www.simplyhost.biz

The best shared hosting package is the Business package where you will get 15 gb of web space and 300 gb of bandwidth. It’s all for just USD 65 (RM207) per year. I throw in together Free Domain name with the package. Actually all shared hosting package got this free domain name.

I also have VPS, semi dedicated server and dedicated server. Check it out at my website simplyhost.biz. Take a look also at all the features available. A lot!

Come and give support to me :)

Poslaju Volumetric Charge

I had this surprising experience with Poslaju. I am posting the Double Din player to Sarawak. After done packing in the box with enough padding. With Poslaju you ought to put extra padding, no one knows how they handle the package, why take the risk?

Ok. So I drive happily to Poslaju HQ at Rawang. I purposely going there… Just want to find out where is this Poslaju HQ at Rawang. So next time if I need to pickup the undelivered items, easier for me to go.

Once there I bring the box. The counter guy said, put it direct on the scale. I go and fill in the form. After few moments he got up and start weight the box. It weight 4.1 Kg only. Then he mention, this box cannot charge by weight, but by volumetric scale. I was like puzzle… I ask how much? (The right thing to ask when you don’t know a thing… lol)

He measure the box, do some calculation.. And then he said “RM85.70″. I was like WHATTT?? But I kept it cool. Haha. He explain more that the box is big, but really weight a little bit only. This big box will take up space, thus need to charge by volumetric.

I am shocked! Because I expect it should be around RM50 or so. Just check it online that it said for 5kg weight, only RM43 not inluding taxes. Back then I think… Duh! How much taxes going to cost… Not cost more than RM50. Surely I am. Little did I know…

Well… To sum it up. It’s better to go to the nearest Poslaju office (post office). It’s just the same. Better if office that is closer to any ATM so you can withdraw money should you run short of changes. You don’t know ok. Lucky I did bring RM100 that day.

So to Sarawak buyers, I will try to keep the box smaller to avoid the volumetric charge. I’ll find out later what is the maximum scale of weight before they charge by volumetric.

Hulu Selangor Done?

I am actually don’t really care at first about Hulu Selangor election. Because I think no matter what PKR will win. I mean… PKR might just lose majority but still win it. That is my believe and I just don’t mind at all.

Then they put Zaid Ibrahim there. I start to worries. But I think Zaid is credible man, he should be able to capture the heart of Hulu Selangor people. He should… But that didn’t happen.

But few days ago when I heard about Felda settlement. I think… Damn! This is the most precious card that BN can play. And it proves with BN winning Hulu Selangor election.

You all can go search about Felda Sungai Buaya issues. But what I heard on radio (I think Selangor FM) one of the caller said thank you and this should be done earlier, when his father was still alive.

Ouch! This is very well played tactics! Very good indeed. I read that even MB Khalid also announce to form some committee on the Felda issues. Come on Khalid, you should’ve tackle this issue earlier, like within 1 year in your office. Not 1 day before election, that is just the same with BN. Why copy paste?

Anyway… I would like to read on other credible analysis about BN win (or PKR lose). Hunt for article now!

Techno & Trance song

My partner in FYP used to make faces when I start to listen to my preferred song to help me during our FYP project development. Why? I used earphone, but I turn it so high that it can be heard quite loud. Lol.

Not only her (my partner), my gf also hate this kind of song. When I blast this music in my car she would scream that this music make her head hurts. Ouch! Maybe I did blast it too loud :P Lol again.

I don’t remember when did I start to like this kind of music. When I was teenager I used to listen to Malays pop song. From Siti Nurhaliza to those boy band (forget already). All about love. Bla bla bla.

Then I start to know Butterfingers. I save my school money to buy their original cassette. Then I start to know those underground music. Start buying ROTTW mags.

But I dont recall when did I start to listen to this kind of music.

What I like is, it make me type faster (with minimal error) and not making me sleepy staring at the monitor with all those line of codes! As far as I know nobody in my circle of friends enjoy the same music as me.

I dont go to club though. So I dont know the DJ or the competition or whatever (to write like this shows that I dont know anything about it, haha). I prefer to listen in my complete privacy.

This is how I enjoy the music :) Its great. You should try it.

KAIER Headlight Booster + Osram Bulb

Introducing new products for this month. KAIER Headlight Booster for H4 socket and Osram Bulb.

KAIER Headlight Booster

KAIER Diagram

OSRAM Bulb to pair with KAIER Headlight Booster

OSRAM Bulb in Flesh

KAIER Headlight booster take power directly from battery. Its also have its own relay and fuse. So it is like replacing with new cable and relay altogether for your bulb. So it will make your headlight brighter like new.

Best if you also upgrade to OSRAM bulb. It’s 100/90w bulb. Mark for offroad, but can use for normal road lah. Many people have upgrade to 100w bulb no problems. KAIER wiring have no problem handling 100w bulb, just make sure your socket is not plastic (like Proton Iswara).

KAIER Headlight Booster is for RM55

OSRAM 100/90w Bulb is for RM50

Buy both for RM100 only (RM5 discount)