Plz. tell me how to write this cipher only attack. I'm desperate.

Question

Hi,
I need to write an attack for a simple substitution-hash cipher. But I seem to have no clue as to how to go about with this. Please help me.
We were given a subtitution key
( for eg:
a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z, ' '
b, a,' ', e, f, g, h, d, k, z, j, i, r, q, s, t, m, n, c, l, o, p, y, w, u, v, x
and a block length for the cipher (for eg: 5)
Each of the characters are numbered 0 (for 'a') to 26 (for ' ')
Now, if the plain text is "I love cryptography" the encryption is done as:
i lov, e cry,ptogr,aphy .(1 space is added as a padding character)
kxisp,
For the next block, the sum of the current block's plain text is taken.i.e, 8(for i) +26
(for ' ') + 11(for l) + 14(for o) + 21 (v) = 80%26=2.
Now for the next block, (e cry) after the given subsitutions are done the hash value of 2 is further added i.e
e ' ' c r y
f x ' ' n u which becomes the following when 2 is added:
h z b p w
Thus giving kxisp,hzbpw. Now the hash is found for e cry and the same process is repeated for the next block.
The entire text is taken at random from a dictionary. Please give me a lead in solving
this problem. The attack should be a ciphertext-only program.
Thanks,
Phani

Answer 1

"Other" is data that the iPod doesn't know how to deal with (but on your nano, it isn't Apps). All iPods have some quantity of "Other" on them. Sometimes Other is corrupt files that cannot be read.
The usual remedy when the quantity of Other becomes too big, is to Restore the iPod. However, 0.26GB of Other doesn't appear to be very much and I suspect you won't see much change, if any, if you Restore.