Question

How many rows will the letters of the plain text occupy in the table, that is used for encryption in columnar transposition cipher when a given keyword is “SECRET” and plain text is “SANFOUNDRY”?

(a) 1

(b) 2

(c) 3

(d) 4

I have been asked this question during an interview for a job.

I need to ask this question from Cryptography topic in portion Cryptography of Data Structures & Algorithms II

Answer 1

Right option is (b) 2

The explanation is: The number of columns in the table used for the purpose encryption in columnar transposition cipher will always be equal to the number of letters in the keyword.So when we will write the letters of the plain text row wise then there will be 2 rows of plain text in this case. The table is shown below :-

S E C R E T

1 S A N F O U

2 N D R Y