The Nino Cipher

H(K)
K
[3]
K
[2]
K
[1]
K
[0]
101
32
24
16
8
0
102
HE(K0)
111
110
HE(K3)
HE(K3)
HE(M3)
HE(K2)
HE(K1)
HE(M2)
HE(M3)
108
103
105
104
HE(M1)
HE(M0)
107
0 1 2 3 4
HE(K1)
HE(M1)
5 6 7 8
C[0] C[1] C[2] C[3] C[4] C[5] C[6] C[7]
106
HE(K2)
HE(M2)
109
8
8
XOR(K1)
XOR(K1)
M[0]
M[1]
M[2] M[3] M[4] M[5] M[6] M[7]
SECURITY GUARANTEE ZONE (M1)
SECURITY GUARANTEE ZONE (M2)
INSECURITY GUARANTEE
ZONE (M1)
112 113
114 115
8
8
INSECURITY GUARANTEE
ZONE (M2)
FIGURE 1: Equivocation Graphs of 4 message information types.
From the equivocation graphs of the 4 message types above, the following observations can be
made:
• The key entropy H(K) is denoted on the Y-Axis, whilst the number of characters are
denoted on the X-axis. Both the Y and X axis are logarithmic, allowing projections for keys
and messages of any size and length.
• All message equivocations H E(M) begin with a value of 0 at 102.
• All key equivocations H E(K) begin with a value of 32 at point 101, since they all use the
same 32-bit key K.
• The H E(M) and H E(K) of all messages meet at their respective perfect secrecy points – M0
(107), M1 (105), M2 (108) and M3 (110).
• The height of each perfect secrecy point is determined solely by the amount of information
in the message type, with the lowest being M0 (the known plaintext) and the highest being
M3 (the random string).
• The slopes of H E(M) and H E(K) for each message type are solely determined by the amount
of information in the language message type, not the key. Ordinarily it is the language used
which solely determines the slope of the key and message equivocations.
© Helder Figueira - Perpetual Encryption 2017