<s>
In	O
cryptography	O
,	O
the	O
Davies	B-Algorithm
attack	I-Algorithm
is	O
a	O
dedicated	O
statistical	O
cryptanalysis	O
method	O
for	O
attacking	O
the	O
Data	B-Algorithm
Encryption	I-Algorithm
Standard	I-Algorithm
(	O
DES	B-Algorithm
)	O
.	O
</s>
<s>
It	O
is	O
a	O
known-plaintext	O
attack	O
based	O
on	O
the	O
non-uniform	O
distribution	O
of	O
the	O
outputs	O
of	O
pairs	O
of	O
adjacent	O
S-boxes	B-Algorithm
.	O
</s>
<s>
It	O
works	O
by	O
collecting	O
many	O
known	O
plaintext/ciphertext	O
pairs	O
and	O
calculating	O
the	O
empirical	B-General_Concept
distribution	I-General_Concept
of	O
certain	O
characteristics	O
.	O
</s>
<s>
The	O
Davies	B-Algorithm
attack	I-Algorithm
can	O
be	O
adapted	O
to	O
other	O
Feistel	B-Algorithm
ciphers	I-Algorithm
besides	O
DES	B-Algorithm
.	O
</s>
