Week12
- 1. Introduction to How Encryption Works When it uses the Internet, we do not just necessarily click it in the circumference, and it is necessary to send information of our own to other people at our much time of the - online which does not understand information (a news peg to read, for example, or blog contribution) passively. I need that it enters by many secret personal information to give an order for anything about the Internet regardless of whether or the book from its contracting an online vendor or the online account, a CD are something elsewhere. As for our name, e-mail address and physical address and number of the telephones, password, the typical duties may not include only a password (PIN) either. We lived in the surprising growth of the Internet and excited a company and consumers like by the promise to change a method to act. While I sit down before a laptop, it is easy at all I sell and buy a product all over the world, and to do it. However, the preservation is main concern on the Internet when I use it because you in particular send a confidential information between a party.
- 2. Symmetric Key (1) Like two Spartan generals sending a message each other, the computer which I use the symmetry-shaped key coding for to send information among each other must comprise the same key. There is private key (cord) which I can use because it encrypts one information to each computer before it is sent to another computer in key to symmetry form coding about a network. The key of the symmetry form obliges it to what you understand which computer talks towards each other so that you can install a key on each. The key coding of the symmetry form is the same as the secret cord which you must know because each of two computers decodes information basically. The cord provides a key in decoding a message.
- 3. Symmetric Key(2) Please think about it in this way: You make the coded message which 2 sends to the friend whom each letter is exchanged with in a letter below from it in the alphabet. Thus "A" becomes "C" and "B" becomes "D". You already told a trusted friend that a cord "was a shift by 2". Your friend gets a message and interprets it. Anyone to see a message other watches only nonsense. The same thing goes for a computer, but of course keys are usually long by an emergency. The algorithm of the first main symmetry form developed for a computer in the United States of America was Data Encryption Standard (DES). And it was approved to use it in the 1970s. DES uses the key to 56 bits.
- 4. Symmetric Key (3) A key of -56 bits was able to easily decode data encrypted in the shortstop who provided combination (70 quadrillion) (attack of the violence) (I try every possible combination to merely find a right key) that could be to 1 quadrillion more than 70 since a security expert of the 70s did not think already even if it was fixed DES because a computer became higher-speed. DES was exchanged with Advanced Encryption Standard (AES) afterwards. And it uses the key to 128, 192 or 256 bits. Most people think that it is enough coding standards for the long time when AES comes: For example, the 128 bits key can have things more than 300000000000000000000000000000000000 key combinations
- 5. Hashing Algorithm (1) The key to public key encryption is based on hash value. This is value calculated from a base input number using algorithm performing a hash. The hash value is a summary of the first value basically. The important thing about the hash value is that it is almost impossible to draw an original input number without knowing the data which are used to make hash value. There is the simple example here: Input number Hashing algorithm Hash value 10,667 Input # x 143 1,525,381
- 6. Hashing Algorithm (2) You can watch it how difficult it is to be settled when value 1,525,381 came out of an increase of 10,667 and 143. However, it will be very easy to calculate value 10,667 if you know that a multiplier is 143. As for the public key encryption, the fruit is very more complicated than this example, but it is a basic thought. The public key including the number of 40 bits or 128 bits is clear, and, for coding, use the complicated algorithm and very considerable hash level generally. - this having a combination varying in 2128 or 340282366920938463463374607430000000000000000000000 0000000000000000 with the possibility seems to be going to find one specific sand to the number of 128 bits in the Sahara.