Cryptology - Unofficial St. Mary's College of California Web Site

5.7. ARISTOCRATS 79
the 69971 or 4207 so 1984 like 1290
of 36411 have 3941 said 1961 our 1252
and 28852 an 3747 what 1908 over 1236
to 26149 i 3700 up 1895 man 1207
a 23237 they 3618 its 1858 me 1181
in 21341 which 3562 about 1815 even 1171
that 10595 one 3292 into 1791 most 1160
is 10099 you 3286 them 1789 made 1125
was 9816 were 3284 than 1789 after 1070
he 9543 her 3037 can 1772 also 1069
for 9489 all 3001 only 1747 did 1044
it 8756 she 2859 other 1702 many 1030
with 7289 there 2724 new 1635 before 1016
as 7250 would 2714 some 1617 must 1013
his 6997 their 2670 time 1599 through 969
on 6742 we 2653 could 1599 back 967
be 6377 him 2619 these 1573 where 938
at 5378 been 2472 two 1412 much 937
by 5305 has 2439 then 1377 your 923
this 5146 when 2331 do 1363 way 909
had 5133 who 2252 first 1360 well 897
not 4609 more 2216 any 1345 should 888
are 4393 no 2201 my 1319 because 883
but 4381 if 2199 now 1314 each 877
from 4369 out 2096 such 1303 just 872
Figure 5.6: The 100 Most Common Words in English
1. Do a frequency count. Identify which ciphertext letters are most likely
etaoinshr. Be aware, however, that especially in short message, frequencies
can be very strange.
2. Look at the initial and final letters of words. Use this to help identify
which etaoinshr letters are which.
3. Study the short words. There frequently are words like I, a, the and and
present.
4. Work hard. Mix effort with brain power. Remember that brilliant inductive
realizations usually come only after some hard thought.
Example: SDGHKHMP HP TDQJ ZBFXJQDEP KWBF LBQ, YDQ HF LBQ CDE BQJ
DFGC UHGGJZ DFMJ. LHFPKDF MWEQMWHGG Hint: G = l.
Substituting the given G = l gives the word UHllJZ=**ll**. So H and J
must be vowels, and U and Z are probably consonants. The words HP and HF
show P and F to be consonants, and H is perhaps i