Dobryakova, Larisa; Ochin, Evgeny
(Scientific Journals of the Maritime University of Szczecin, Zeszyty Naukowe Akademii Morskiej w Szczecinie,
2014)
In computing, the Least Significant Bit (LSB) is the bit position in a binary integer giving the units value, that
is, determining whether the number is even or odd. We do not use this format. In conventional Intel bit
ordering, the Most Significant Bit (MSB) is numbered 7 and the least significant bit (LSB) is numbered 0:
27 (MSB) 26 25 24 23 22 21 20 (LSB)
D = d7 d6 d5 d4 d3 d2 d1 d0
For example, if on the record of number D = 131 = 10000011 we invert the MSB = 1 into MSB = 0, then
obtain D = 00000011 = 3, but if we invert LSB = 1 into LSB = 0, then distortions are considerably fewer:
D = 10000010 = 130. It is common to assign each bit a position number, ranging from zero to N – 1, where N
is the number of bits in the binary representation used. Normally, this is simply the exponent for the
corresponding bit weight in base-2 (such as in 27, 26, …, 21, 20). In this article to reduce the stego-errors we
use a pair of numbers D1 and D2 and a pair of corresponding LSB d1,0 and d2,0.