Give the summary of the text using the key terms. Historical cryptography

HISTORICAL CRYPTOGRAPHY

Read the following words and word combinations and use them for understanding and translation of the text:

scribe - переписчик

inscription - надпись

substitution cipher - подстановочный шифр

parchment - пергамент

to wind - наматывать

length-wise - по длине

a transposition cipher - перестановочный шифр

to overtake - опережать

grid - решетка

offset - сдвинутый

gibberish - бессмысленный

to intercept - перехватывать

brute force method - подбор методом грубой силы

overconfidence - самонадеянность

to map - преобразовать

stepping switch - шаговый переключатель

renowned - прославленный

Ancient Egypt

The earliest known text containing components of cryptography originates in the Egyptian town Menet Khufu on the tomb of nobleman Khnumhotep II nearly 4, 000 years ago. In about 1900 B.C. Khnumhotep's scribe drew his master's life in his tomb. As he drew the hieroglyphics he used a number of unusual symbols to obscure the meaning of the inscriptions. This method of encryption is an example of a substitution cipher, which is any cipher system which substitutes one symbol or character for another.

As the Egyptian culture evolved, hieroglyphic substitution became more common. This method of encryption was relatively easy to break for those who could read and write. There are several possibilities why the Egyptians would use the sacred nature of their religious rituals from common cryptography is that the scribes wanted to give a formal appearance to their writings. This seems to be very similar to formal complicated language used in any modern legal document. Egyptian cryptography could also have been a way for a scribe to impress others by showing that he could write at a higher level.

Greece

In about 500 B.C. the Spartans developed a device called Scytale, which was used to send and receive secret messages. The device was a cylinder in which a narrow strip of parchment was wound. The message was then written length-wise on the parchment. Once it was unwound the message on the strip of parchment became unreadable. To receive the message an identical cylinder was needed. It was only then that the letters would line up resulting in the original message.

The Scytale is an example of a transposition cipher, which is any cipher system that changes the order of the characters rather than changing the characters themselves. In today's standards, the Scytale would be very easy to decipher, however, 2, 500 years ago the percent of people that could read and write was relatively small. The Scytale provided the Spartans a secure method of communication.

Rome

The earliest recorded military use of cryptography comes from Julius Caesar 2, 000 years ago. Caesar, being commander of the Roman army, solved the problem of secure communication with his troops. The problem was that messengers of secret military messages were often overtaken by the enemy. Caesar developed a substitution cipher method in which he would substitute letters for different letters. Only those who knew the substitution used could decipher the secret messages. Now when the messengers were overtaken the secret messages were not exposed. This gave the Roman army a huge advantage during war.

Caesar typically just shifted his letters by some predetermined number. This number was the cipher key of his algorithm. A randomized order of substitution yields a much larger amount of security due to the larger amount of possible orderings.