Hello, today I will talk about the Turing test, created by Alan Turing, considered the father of computer science, to answer the question "Can machines think?"

You can click on the following topics to jump to the section where I explain them:

[What is the Turing Test?](#m1)

[Examples of the Turing Test](#m2)

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## What is the Turing Test?

Can machines really think? And if they can, how can we prove it? In 1950, Alan Turing introduced the Turing test in his paper "Computing Machinery and Intelligence" to logically answer these questions. Although the test has been widely criticized over the years, it still holds an important place in the philosophy of artificial intelligence. So, how is the Turing test conducted?

<img src="./turingtest.png" alt="test-image" height=400 />
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In the test, there is initially a human evaluator. This evaluator is asked to interact with different individuals through a chat application. The interaction must be in written form, not through voice or video. The group the evaluator interacts with can either consist of only humans or a mix of humans and a machine undergoing the Turing test. The evaluator engages in written conversations with the group for 5 minutes. If the evaluator can identify a machine in the group, the machine fails the test. If there is a machine in the group and the evaluator believes that everyone they interacted with is human, the machine successfully passes the Turing test.
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<img src="./eliza.jpg" alt="eliza-image" height=400 />
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Sixteen years after the test was published, in 1966, Joseph Weizenbaum created a program called Eliza that succeeded in passing the test on some individuals. Eliza essentially behaved like a psychotherapist. It would automatically respond with pre-prepared sentences if it found previously learned keywords in the user's sentences. If no such keywords were found, it used stock responses. Fundamentally, Eliza aimed to prompt the user to talk more by asking questions. This approach convinced many people that Eliza was a real psychotherapist.
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## Examples of the Turing Test

In this section, you can also read the dialogues and try to guess which one is the machine and which one is the human. I will show three examples in total. In these tests, the judges are initially informed that one is a human and the other is a machine, and they are expected to identify accordingly.

<img src="./turing1.jpg" alt="tur1-image" />
<strong>Jury's Guess:</strong> <br/>
The jury guessed that both conversations were with real humans. <br/>
<strong>Actual Result:</strong> <br/>
The conversation on the left is with an adult male, and the conversation on the right is with a machine named Eugene Goostman. <br/>

<img src="./turing2.jpg" alt="tur2-image" />
<br/>
<strong>Jury's Guess:</strong> <br/>
The jury said that the conversation on the left was with a young male and the one on the right was definitely with a machine. <br/>
<strong>Actual Result:</strong> <br/>
The conversation on the left is with a machine named Eugene Goostman, and the conversation on the right is with a real human.
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<img src="./turing4.jpg" alt="tur4-image" />
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<strong>Jury's Guess:</strong> <br/>
The jury guessed that the conversation on the left was with a machine and was unsure about the one on the right. <br/>
<strong>Actual Result:</strong> <br/>
The conversation on the left is with a machine named Ultra Hal, and the conversation on the right is with a real human.
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Source:

<http://www.cambridgeblog.org/2016/10/into-the-intro-turings-imitation-game-conversations-with-the-unknown/>


Turing Test

Hello, today I will try to explain the Schrödinger's Cat thought experiment, which is used to explain what can happen when quantum mechanics, which is quite famous, is applied to large systems.

## Schrödinger'in Kedisi

The Schrödinger's Cat experiment was proposed by physicist Erwin Schrödinger in 1935. The main purpose of this experiment is to observe that applying an event that can occur in subatomic particles, such as superposition, to large systems can yield very interesting results.

<img src="./cat-formula.jpg" alt="formula-image"  />

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To understand this experiment, I must first talk to you about the principle called superposition. To explain superposition in the simplest way, we can use what we call a qubit, a type of bit used in quantum computers. As we know, in normal computers, bits can be either 1 or 0. Qubits, however, can be both 0 and 1 at the same time. If there is a 50% chance of a qubit being 0, then there is a 50% chance of it being 1. This way, a qubit can take 2 values. But if we try to measure this qubit, it will give us either a 0 or a 1 value. Each time we measure, we have a 50% chance of getting 0 or 1. But we can never know whether the qubit is 0 or 1 without measuring it. This situation is called superposition.
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<img src="./sch-cat.png" alt="cat-image"  />


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The Schrödinger's Cat thought experiment can be explained with different examples, but today I will explain it in the most basic way. In the experiment, a cat is placed inside a box, and the box is closed. Inside this box, there is a radioactive source with a 50% chance of decaying and a monitor that checks whether the radioactive source has decayed or not. If the radioactive source decays, the monitor detects it and releases a poison into the box that will kill the cat. We can never know whether the cat is dead or alive without opening the box. When we open the box, we observe the cat as either dead or alive. So, in fact, by looking at it, this experiment puts a cat in a superposition state as well. Therefore, until we open the box, we accept that Schrödinger's cat is both dead and alive.



Schrödinger’s Cat

Hello, in this article, I will talk about the Enigma machine, which holds a very important place in the history of encryption. Even Alan Turing tried to break its codes, and documentaries and movies have been made about it.

Click on the following topics to jump to the respective section.

[History and Structure of Enigma](#m1)

[How Enigma Works](#m2)

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## History and Structure of Enigma

Enigma is an encryption machine used to encode a message and decode messages encoded by itself when operated with the correct settings. Enigma was first produced in Germany at the end of World War I by Arthur Scherbius. Initially, it was mainly used in the private sector to securely transmit information. The first versions produced had only 3 or 4 rotors.

<img src="./enigma.jpg" alt="enigma-image" />

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Over time, with the outbreak of World War II, the German army decided to use Enigma for secret communications within the military. To make the rotor-only version of Enigma more secure, a component with 26 sockets was added to the bottom of Enigma, one for each letter, to change the encryption of letters. This made breaking the codes even more difficult. As a result, during World War II, the United States and the United Kingdom jointly gathered the best scientists, mathematicians, and engineers in the field to develop a system to break Enigma's codes. This team, with the help of Alan Turing and Gordon Welchman, used a machine called "Bombe" to quickly find Enigma's daily settings.

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## How Enigma Works

The use of Enigma to encrypt a message or to decrypt an encrypted message is the same. For Enigma to work correctly, both the person encrypting the message and the person wanting to decrypt this encrypted message must set the machine to the same settings. Once the machine is set to the correct settings, you enter the text you want to encrypt, and a text of the same length as the original text is produced. When you want to decrypt a message, you enter the encrypted text, and you get the original text in the end. The basic principle of the machine is to convert one letter to another. That is, encryption is not done by the word but specifically by the letter. Each letter is converted to a different letter based on the settings. Enigma operates based on three main settings.

* The value of the rotors

* The order of the rotors

* The configuration of the sockets

<h4>1-Value of the Rotors:</h4>

Enigma typically has 3 rotors. Each rotor has a value. These values are numbers between 1 and 26. Sometimes letters from A to Z are used instead of these numbers, but this doesn't create a difference in the system because the German alphabet has 26 letters. To make it easier to understand, I will use numerical values in the explanation. Let's assume the values of our rotors are (5 12 24). Every time a value is entered, Enigma will increment the value of the rightmost rotor by 1. So, if a letter is typed into the machine, the values will change to (5 12 25), and if another letter is typed, the values will change to (5 13 0), similar to the odometer in cars. The values of the letters always change based on these three values. Even if the same letter is entered three times in a row, the encrypted letters will be different. In this way, 17,576 different value configurations can be set.

<img src="./enigma-rotor.png" alt="enigma-rotor-image" width=600 height=400 />

*(A rotor using letter values instead of numbers)*

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<h4>2-Order of the Rotors:</h4>

Each rotor is not identical. The three rotors have different internal structures. There are three types of rotors: I, II, and III. These rotors can be interchanged among each other. For example, the rotors can be arranged in the order (I II III) or (II III I). This allows for 6 different configurations of the rotors. When combining the values and the order of the rotors, the machine can be set in 105,456 different ways. When we see this number, it might seem that a group of people could find the correct setting within a day by trying each setting. However, the next level of setting greatly increases the complexity of Enigma.

<h4>3-Configuration of the Sockets:</h4>

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<img src="./enigma-plugboard.jpg" alt="enigma-plugboard-image" width=600  />


*(The part with the sockets)*

As you can see in the image above, Enigma has 26 sockets. In the picture, the letter A is connected to J, and the letter S is connected to O. As a result of these connections, the values of the letters are swapped with each other's values. According to the example in the picture, if the user presses the letter A, it takes the value of the letter J. Similarly, pressing J will take the value of A. In the picture, we only see two pairs, but during the war, the German army increased the complexity by using 10 pairs. Finally, when all values are included, the machine can be set in 158,962,555,217,826,360,000 ≈ 2^67 different ways. This makes it highly unlikely to find the setting by trial and error.

---

As you can see, Enigma was a very good encryption machine for its time, but this does not change the fact that it had major issues. The biggest problem with Enigma was that both parties needed to set the same settings. The settings were provided as a monthly list indicating which setting to use on which day to the departments using the machine. However, if this list fell into the hands of an enemy through an agent or any other means, it created a significant issue for the side using the machine. Therefore, delivering the list securely required significant effort and attention.



*(A real settings list)*

Overall, Enigma held an important place in both the private sector and the military for its time. If you are interested in such topics, I recommend watching the movie "The Imitation Game," which talks about Alan Turing and Enigma. If you want to use Enigma yourself, you can try the Enigma simulation from the link.

Source:

* <https://en.wikipedia.org/wiki/Enigma_machine>

*  <https://www.youtube.com/watch?v=d2NWPG2gB_A&t=303s&ab_channel=Computerphile>

Enigma Machine

Hello, in this article, I will talk about a type of data storage that we often hear about through warnings when we visit websites, known as cookies.

You can click on the following topics to jump to the section where I explain them:

[History of Cookies](#m1)

[What are Cookies](#m2)

[Types of Cookies](#m3)

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## History of Cookies

Cookies were first created in 1994 by Lou Montulli. The company Lou worked for, Netscape, was developing an e-commerce site for another company. On this site, the products added to the user's cart were stored on the site's server, which caused a significant storage issue. Therefore, they asked Lou to find a solution that would store this data on the user's computer instead of the server.

<img src="./lou_mont.jpg" alt="lou-image"  width="500" height="550"/>

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In response, Lou Montulli and John Giannandrea developed a cookie system that was supported by Netscape's own browser, Netscape Navigator, in the same year. The first cookie used was to check if the user had visited the site before. After Netscape Navigator, Internet Explorer also started using cookies, and the usage of cookies began to increase.

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## What are Cookies

You have probably encountered cookies through warnings like "This website uses cookies to ensure you get the best experience" or "By entering this site, you agree to the use of cookies." So, what is the reason for these warnings?

<img src="./cookie.png" alt="cookie-image"  width="650"/>

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Cookies are a type of data packet stored in our browser and kept specific to the site we visit. They improve our experience on the site through functionalities such as the "Remember Me" button, setting the language option on the site, and the shopping cart on e-commerce sites. Besides these uses, cookies are most commonly used for advertisements. For example, information about which products we viewed or purchased on e-commerce sites is processed to shape our future ads accordingly. Additionally, on social media applications, liked photos or searches made on search engines are stored in cookies, and ads are displayed according to our interests.

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<img src="./cookie_notice.jpg" alt="cookie-notice-image"  width="650"/> 

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Cookies start storing such comprehensive information from the moment we enter the site. Since storing this type of information without the user's consent is illegal, sites that use cookies are required to display a warning like the ones we mentioned at the beginning, asking for the user's permission when they first enter the site.

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## Types of Cookies

The basic structure of cookies includes the site from which the cookie originates, the name of the cookie, the value within the cookie, and the expiration date of the cookie. Cookies are generally divided into two types: first-party cookies and third-party cookies. First-party cookies are used for processes that improve our experience on the site we are visiting. The domain part of first-party cookies must be the same as the site we are on.

<img src="./cookie_struct.png" alt="cookie-struct-image"  width="650"/> 

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Third-party cookies, on the other hand, are created when the domain part of the cookie is different from the site we are on. These cookies are used by advertisers or analytics companies. For example, they track which sites the user visits, which products they view, and which products they purchase to create future ad suggestions accordingly.

To prevent these types of cookies from tracking us without our knowledge, specific regulations were introduced. Laws such as the General Data Privacy Regulation (GDPR) and the California Consumer Privacy Act (CCPA) were enacted. As a result of these laws, certain requirements were established for websites:

* Inform users that your site uses cookies.
* Give users the right to prevent some or all cookies from being collected.
* Allow users to use most of your site without receiving cookies.

---

Even though it has a very simple structure, the significant revenue of companies like Google and Facebook today comes from ads made possible by the use of cookies. If you want to see the cookies in your browser, you need to press Control+Shift+J, select the Application tab in the top panel, and find the Cookies option in the left panel. Here, you can see all the cookies used on the current page you are on.

Source:

* <https://en.wikipedia.org/wiki/HTTP_cookie>
* <https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies>

What is Cookies

Hello, in this article, I will explain blockchain technology, which plays a fundamental role in the functioning of cryptocurrencies that we have been hearing a lot about lately. Since blockchain is not used in just one field, I will generally discuss its use in cryptocurrency systems in this article.

You can click on the following topics to jump to the section where I explain them:

[History of Blockchain][#m1]

[Public Blockchain][#m2]

[How Blockchain Works][#m3]

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## History of Blockchain

The foundation of blockchain technology was laid by cryptography experts Sturat Haber and Scott Stornetta in 1991. In these studies, the information to be stored was first hashed to create a block. These blocks are kept with a timestamp, a piece of data that records when the information was recorded. As a result of keeping these blocks in a list, the data is stored.
<br></br>

<img src="./bitcoin.png" alt="bitcoin-image"/>

<br></br>
On October 31, 2008, a group or individual named Satoshi Nakamoto published a paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System." Today, money transfer transactions are carried out through a traditional method where a third institution is involved and approves the transactions. This paper described a system where transactions could be conducted more securely, without a central authority, anonymously, and without involving a third institution. This system was fundamentally built on blockchain technology. The currency used within this system is Bitcoin, the first cryptocurrency most of us have heard of.

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## Public Blockchain

A public blockchain is a type of blockchain. As I mentioned at the beginning of my article, I will discuss the blockchain technology used in cryptocurrencies. Cryptocurrencies generally use public blockchains. In cryptocurrencies, transactions are carried out by looking at the blockchain, where all information such as how much money someone has sent and received is kept. By looking at this list, the balance of individuals is calculated. In a public blockchain, the list of blocks is shared with everyone. Since the list with blocks is stored by everyone, if someone tries to alter the list to increase their balance, it will be deemed incorrect because it does not match the other lists in the system. Thus, transactions are recorded securely. Bitcoin, Ethereum, Litecoin, and similar cryptocurrencies use public blockchain.

<img src="./blocktype.png" alt="type-image" />
Advantages:

* Everyone can participate in the public blockchain.
* The security increases with the number of participants.
* It is a transparent system that everyone can see.

Disadvantages:

* The transaction speed can be slow.
* The system slows down as more people join.

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## How Blockchain Works

In cryptocurrency systems, blockchain is the main structure. Each block contains the amount of money sent, the public keys of the sender and receiver, a timestamp, the previous hash, and a value called nonce. These pieces of information are hashed according to a certain rule when used or changed. However, to ensure security, hashing the information inside is not enough. Each user in a cryptocurrency system has their own wallet. For this wallet, the user is given two keys: a private key and a public key. The public key is generated as a result of processing the private key. The public key is the key we can share with everyone. It functions similarly to the IBAN information we use today, appearing as the receiver or sender information during transactions.

<img src="./blocks.png" alt="blockchain-image" />

<br></br>

The private key, on the other hand, is information that only the wallet owner should know. When the user creates a new transaction, a new hash is generated using the transaction information and the private key. This hash is called a signature. To ensure the security of the transaction, besides the initial hashing, the signature value is also checked. The sender's public key, transaction information, and signature value are checked by an algorithm to see if they match each other. If this check is passed, the transactions in this block are approved, and the block is added to the blockchain.

These processes generally require significant computational power, so the confirmation time of transactions in cryptocurrencies can vary depending on the algorithm used. For example, in Bitcoin, the total time for transaction confirmation and block creation is on average 10 minutes. The computers performing these calculations are rewarded differently depending on the system. For example, in the Bitcoin system, the user performing the calculations is rewarded with a certain amount of Bitcoin for creating a block and also receives a transaction fee for the performed transaction.

---

With the increasing popularity of cryptocurrencies, making transactions with them has become much easier. If you want to own a cryptocurrency wallet, all you need to do is visit the site of the cryptocurrency that interests you and create a new wallet. However, if this seems difficult to you and you only want to trade cryptocurrencies, this is now much easier. You can easily create an account and trade on sites like Coinbase and Binance. Finally, if you want to see how blockchain works in a detailed and modeled way, you can check out this site: [Anders Brownworth Blockchain Demo](https://andersbrownworth.com/blockchain).

Source:

* <https://andersbrownworth.com/blockchain/>

* <https://data-flair.training/blogs/blockchain-tutorial/>

* <https://101blockchains.com/types-of-blockchain/>

* <https://www.btcturk.com/bilgi-platformu/blockchain-blokzinciri-teknolojisi-nedir/>

Ahmet Salih Ozmen

Turing Test

Hello, today I will talk about the Turing test, created by Alan Turing, considered the father of computer science.

Schrödinger’s Cat

Enigma Machine

What is Cookies

What is Blockchain