Below we show the decoder disc for the Caesar cipher shifting by 3 characters.

Click on the arrows  ⤿  or  ⤾  to turn the inner disc and decrease or increase the shift.

 Shift by 3 characters   Shift by 11 characters 

(a) Encryption From the disc we can read of the imagess of J at the elements of the domain of J

J(-)=x, J(a)=y, J(b)=z, J(c)=-, ..., J(x)=u J(y)=v J(z)=w

We encrypt the word

chariot

with this Caesar cipher that shifts by 3 characters. We have

J(c)=-, J(h)=e, J(a)=y, J(r)=o, J(i)=f, J(o)=l, J(t)=q,

Thus we encrypt chariot as

-eyoflq

(b) Decryption The images of the inverse J-1 of J at the elements of the codomain of J are

J-1(-)=c, J-1(a)=d, J-1(b)=e, J-1(c)=f, ... J-1(x)=-, J-1(y)=a, J-1(z)=b

We decrypt

qebxafbxfpx-ypq

with this Caesar cipher that shifts by 3 characters. We have

J-1()=t, J-1()=h, J-1()=e, J-1()=-, J-1()=d, J-1()=i, J-1()=s, J-1()=c, J-1()=a

Thus the plain text is

the-die-is-cast