Encrypt the message "SECRET MESSAGE" using a $4$x$4$ ROUTE cipher with the keyword "ENIGMA" First Row: $"$E N I G M A$"($Keyword without duplicates$)$ Second Row: $"$C D T B F H$"($Remaining letters starting from $"$C$")$ Third Row: $"$L O P R$"($Continues filling with remaining letters$)$ Fourth Row: $"$S Q U W$"($Fills the remaining squares$)$ Last Row: $"$X Y Z K$"($Includes the leftover letters to complete the alphabet$)$ Keyword in First Row: The first row is filled with a chosen keyword, in this case, "ENIGMA". Duplicate letters within the keyword are removed $($hence no $"$M$").$ Filling Remaining Squares: The remaining squares are filled with the remaining letters of the alphabet, excluding those already used in the keyword. This is done in a sequential order, going row by row until the entire square is filled.