Reference algorithm in Excel by V.F. Shatalov

Pedagogue-innovator Viktor Fedorovich Shatalov in the 70s of the last century developed a training system using reference signals - interconnected keywords, conventional signs, figures and formulas with a brief conclusion [1].

A reference algorithm in Excel is a set of images and algorithms (formulas), located in a special way on an Excel sheet, which helps to 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 cryptography class.

Following Shatalov’s methodology, the sequence of actions is as follows:

First stage . A figuratively emotional explanation of the teacher material. You can also use the video tutorial from the Khan Academy on the basics of cryptography:

Second stage . A concise presentation of the training material using the Excel algorithm.

Fig. Diffie-Hellman Reference Excel Algorithm

Decryption of the 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 shared key 12 -> = OSTAT (F7 ^ C6; F16)
As a result, they have a shared key 12, which does not know Yves.

Further ... consolidation of material, problem solving, use of the CrypTool program, network exchange between students studying encrypted messages.

Similar Excel-algorithms can be found on the network, for example, Caesar, Viginer, Enigma, but did not find the name of this technique in pedagogy.

References:

"Https://ru.wikipedia.org/wiki/Shatalov_Viktor_Fyodorovich
" https://ru.wikipedia.org/wiki/Diffie_profile_—_Hellman