OLDER CRYPTOGRAPHIC METHODS
Cryptography is one of the oldest fields of technical study we can find records of, going back at least 4,000 years. It is quite noteworthy that of all the cryptosystems developed in those 4,000 years of effort, only 3 systems in widespread serious use remain hard enough to break to be of real value. One of them takes too much space for most practical uses, another is too slow for most practical uses, and the third is widely believed to contain serious weaknesses. Cryptologists still use some old time methods such as just using the old Mesopotamian technique known as “atbash.” This is when they utilize the “atbash alphabet” or now known as the “cipher alphabet,” which is a backwards alphabet, and the letters correlate with the letters of the normal alphabet in order to rewrite and code text. In this method, the last letter of the alphabet is replaced by the first, and vice versa. The table below displays the alphabet used.
Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Cipher: ZYXWVUTSRQPONMLKJIHGFEDCBA
For example, the following table gives a translation of this sort for English. The word "HELLO" becomes "SVOOL" (Cohen).
There are also the methods of using tables and different alphabets that make coding and encrypting messages easier. There is also the main four tasks of making a site or message safe. They are Confidentiality, which is making sure only some people can read it. Authentication is when they can check that that the sender is who they say they are. Integrity is when they make sure that the data has not been altered in any way. Non-Repudiation is when they make sure the receiver can see who sent it (Esslinger). Another Greek method was developed by the then mathematician Polybius and was known as the Polybius Method (now called the "Polybius Square"). The letters of the alphabet would be laid out in a five by five square (similar to the later Playfair method) with i and j occupying the same square. Rows and columns are numbered 1 to 5 so that each letter has a corresponding (row, column) pair. These pairs could easily be signaled by torches or hand signals. Decryption consists of mapping the digit pairs back into their corresponding characters. This system was the first to reduce the size of the symbol set, and in a loose sense it might be considered the forerunner of modern binary representations of characters.
\ 1 2 3 4 5
\_________
1|A B C D E T=54
2|F G H I J H=32 5344 44 4435
3|K L M N O I=42 4224 24 3211
4|P Q R S T S=44
5|U V W X Y/Z
“Polybius Square”
Think of decrypting the Polybius square method as playing BINGO; you line up the rows and columns to find out the position of the letter. This method was widely used during their time and is sometimes used today, however computers make it a little easier to crack (Cohen).
Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Cipher: ZYXWVUTSRQPONMLKJIHGFEDCBA
For example, the following table gives a translation of this sort for English. The word "HELLO" becomes "SVOOL" (Cohen).
There are also the methods of using tables and different alphabets that make coding and encrypting messages easier. There is also the main four tasks of making a site or message safe. They are Confidentiality, which is making sure only some people can read it. Authentication is when they can check that that the sender is who they say they are. Integrity is when they make sure that the data has not been altered in any way. Non-Repudiation is when they make sure the receiver can see who sent it (Esslinger). Another Greek method was developed by the then mathematician Polybius and was known as the Polybius Method (now called the "Polybius Square"). The letters of the alphabet would be laid out in a five by five square (similar to the later Playfair method) with i and j occupying the same square. Rows and columns are numbered 1 to 5 so that each letter has a corresponding (row, column) pair. These pairs could easily be signaled by torches or hand signals. Decryption consists of mapping the digit pairs back into their corresponding characters. This system was the first to reduce the size of the symbol set, and in a loose sense it might be considered the forerunner of modern binary representations of characters.
\ 1 2 3 4 5
\_________
1|A B C D E T=54
2|F G H I J H=32 5344 44 4435
3|K L M N O I=42 4224 24 3211
4|P Q R S T S=44
5|U V W X Y/Z
“Polybius Square”
Think of decrypting the Polybius square method as playing BINGO; you line up the rows and columns to find out the position of the letter. This method was widely used during their time and is sometimes used today, however computers make it a little easier to crack (Cohen).
NEWER TECHNIQUES
Now in present time, computers and technology have made the concept of crypto very valuable and more modern. With the use of new computers and the internet, there comes the need to keep everything safe and protected. There is a specific process that occurs in order to classify something as safe. They must check the authenticity of the person’s identity; they must then make sure that only that one person can receive that message; then they must make sure that the message is legitimate and hasn’t been changed, and next there is the application of non-repudiation, which is the assurance that the sender really sent the message. In order to properly encrypt and decrypt messages, there is the application of different algorithms. These algorithms include Secret Key Cryptography, Public key Cryptography, and Hash Functions (Kessler). Secret Key Cryptography is when only one key is used for both encryption and decryption. Public Key Cryptography uses a different key for each type. Hash functions use math and cryptographic concepts in order to encrypt information. These different algorithms are used to ensure the safety and authenticity of messages and code throughout the internet.
Cryptologists also use different techniques to solve or create codes. Steganography is a technique used for many centuries that consist of written codes and texts that are either just written in encryption, or are written in invisible ink or in secretive scheme. Cryptography is not always just the encryption and jumble of words or letter to make it unreadable, but is sometimes used in a riddle format that simply makes the message different and only understandable to few. Transposition is the technique of jumbling or rewriting the actual letters or words in order to make it unreadable. Plain text is the use of the alphabet to compose an original message and cipher text is when the use of the cipher alphabet can change or alter the original message (Mathai). Many people mix up the concepts of cryptanalysis with cryptography. Cryptography is primarily about the act and study of codes and ciphers, as well as their usage in encryption and decryption, which deals with hiding and concealing messages. Cryptanalysis is the art of cracking the codes or ciphers without knowing the key to the encryption. In the early history of crypto, there was the usage pre-electronics and computers, by simply recording what they could of ciphertext on a piece of paper. There was much incorporation of this type of crypto by the military and government during World War I. Post World War I, there was the addition of technology into the hand and it truly changed the way of crypto and made it that much more important. The addition of telegrams, telephones, and the transfer from electromechanical to electrical devices added more necessity towards cyber encryption and security (Simmons).
Cryptologists also use different techniques to solve or create codes. Steganography is a technique used for many centuries that consist of written codes and texts that are either just written in encryption, or are written in invisible ink or in secretive scheme. Cryptography is not always just the encryption and jumble of words or letter to make it unreadable, but is sometimes used in a riddle format that simply makes the message different and only understandable to few. Transposition is the technique of jumbling or rewriting the actual letters or words in order to make it unreadable. Plain text is the use of the alphabet to compose an original message and cipher text is when the use of the cipher alphabet can change or alter the original message (Mathai). Many people mix up the concepts of cryptanalysis with cryptography. Cryptography is primarily about the act and study of codes and ciphers, as well as their usage in encryption and decryption, which deals with hiding and concealing messages. Cryptanalysis is the art of cracking the codes or ciphers without knowing the key to the encryption. In the early history of crypto, there was the usage pre-electronics and computers, by simply recording what they could of ciphertext on a piece of paper. There was much incorporation of this type of crypto by the military and government during World War I. Post World War I, there was the addition of technology into the hand and it truly changed the way of crypto and made it that much more important. The addition of telegrams, telephones, and the transfer from electromechanical to electrical devices added more necessity towards cyber encryption and security (Simmons).