Question

Tabula recta consists of _______________

(a) 26 rows and 26 columns

(b) 26 rows and 1 column

(c) 1 row and 26 columns

(d) 27 rows and 27 columns

This question was posed to me in a job interview.

The doubt is from Cryptography in portion Cryptography of Data Structures & Algorithms II

Answer 1

Right answer is (a) 26 rows and 26 columns

Easy explanation - Encryption of plain text using running key cipher is done by making use of tabula recta. It consists of 26 rows and 26 columns which have alphabets written 26 times. These are shifted towards left after each row.