Is there a function for inverting the 'reshape' command?

For my rail fence cipher, i obtain the correct output. But am wondering if there is a simple command to decipher the output?

function cipher_text = rail_fence_cipher(origionalText,key)
origionalText = [origionalText,origionalText(1:(key-mod(length(origionalText),key)))];
cipher_text = reshape(origionalText,key,[]);  
end