Reference algorithm in Excel by VF Shatalov

Victor Fedorovich Shatalov, an innovator teacher in the 70s of the last century, developed a training system using reference signals — interconnected keywords, symbols, drawings and formulas with a brief conclusion [1].

The reference algorithm in Excel will be called a set of images and algorithms (formulas), located in a special way on the Excel sheet, which helps activate students' thinking.

I will give an example of using the reference algorithm in Excel, for example, when studying the Diffie-Hellman algorithm in a class on cryptography.

Following the methodology Shatalov sequence of actions is as follows:

The first stage . The image-emotional explanation of the material by the teacher. You can also use watching a video lesson from the Han Academy on the basics of cryptography:

The second stage . Compressed presentation of educational material using the Excel-algorithm.

Fig. Diffie-Hellman support Excel algorithm

Decryption algorithm:

There are two prime numbers 13 and 7 that Alice and Bob know (and is open to Eve).

Alice and Bob come up with two numbers - 3 and 10, respectively.

Then the exchange begins:

Alice sends 5 -> = OSTAT (F17 ^ C6; F16)

Bob calculates the shared key 12 -> = OSTAT (E5 ^ H6; F16)

Bob sends 4 -> = OSTAT (F17 ^ H6; F16)

Bob calculates the shared key 12 -> = OSTAT (F7 ^ C6; F16)

As a result, they have a common key 12, which Yves does not know.

Further ... consolidating the material, solving problems, using the CrypTool program, exchanging over the network between the students encrypted messages.

Similar Excel-like algorithms can be found in the network, for example, Caesar, Vizhinera, Enigma, but I have not found the names of this method in pedagogy.

References:

»Https://ru.wikipedia.org/wiki/Shatalov,_Viktor_Fyodorovich

»Https://ru.wikipedia.org/wiki/Protocol_Diffie_—_Hellman