182 research outputs found
Enhanced secure key exchange systems based on the Johnson-noise scheme
We introduce seven new versions of the Kirchhoff-Law-Johnson-(like)-Noise
(KLJN) classical physical secure key exchange scheme and a new transient
protocol for practically-perfect security. While these practical improvements
offer progressively enhanced security and/or speed for the non-ideal
conditions, the fundamental physical laws providing the security remain the
same.
In the "intelligent" KLJN (iKLJN) scheme, Alice and Bob utilize the fact that
they exactly know not only their own resistor value but also the stochastic
time function of their own noise, which they generate before feeding it into
the loop.
In the "multiple" KLJN (MKLJN) system, Alice and Bob have publicly known
identical sets of different resistors with a proper, publicly known truth table
about the bit-interpretation of their combination. In the "keyed" KLJN (KKLJN)
system, by using secure communication with a formerly shared key, Alice and Bob
share a proper time-dependent truth table for the bit-interpretation of the
resistor situation for each secure bit exchange step during generating the next
key.
The remaining four KLJN schemes are the combinations of the above protocols
to synergically enhance the security properties. These are: the
"intelligent-multiple" (iMKLJN), the "intelligent-keyed" (iKKLJN), the
"keyed-multiple" (KMKLJN) and the "intelligent-keyed-multiple" (iKMKLJN) KLJN
key exchange systems.
Finally, we introduce a new transient-protocol offering practically-perfect
security without privacy amplification, which is not needed at practical
applications but it is shown for the sake of ongoing discussions.Comment: This version is accepted for publicatio
"Gravitational mass" of information?
We hypothesize possible new types of forces that would be the result of new
types of interactions, static and a slow transient, between objects with
related information contents (pattern). Such mechanism could make material
composition dependence claimed by Fishbach, et al in Eotvos type experiments
plausible. We carried out experiments by using a high-resolution scale with the
following memories: USB-2 flash drives (1-16GB), DVD and CD disks to determine
if such an interaction exist/detectable with a scale resolution of 10 microgram
with these test objects. We applied zero information, white noise and 1/f noise
type data. Writing or deleting the information in any of these devices causes
peculiar negative weight transients, up to milligrams (mass fraction around
10^-5), which is followed by various types of relaxation processes. These
relaxations have significantly different dynamics compared to transients
observed during cooling after stationary external heating. Interestingly, a
USB-1 MP3 player has also developed comparable transient mass loss during
playing music. A classical interpretation of the negative weight transients
could be absorbed water in hygroscopic components however comparison of
relaxation time constants with air humidity data does not support an obvious
explanation. Another classical interpretation with certain contribution is the
lifting Bernoulli force caused by the circulation due to convection of the warm
air. However, in this case all observed time constants with a device should
have been the same unless some hidden parameter causes the observed variations.
Further studies are warranted to clarify if there is indeed a new force, which
is showing up as negative mass at weight measurement when high-density
structural information is changed or read out (measured).Comment: Final language corrections based on the galley proof of the published
pape
Totally Secure Classical Communication Utilizing Johnson (-like) Noise and Kirchoff's Law
An absolutely secure, fast, inexpensive, robust, maintenance-free and
low-power- consumption communication is proposed. The states of the information
bit are represented by two resistance values. The sender and the receiver have
such resistors available and they randomly select and connect one of them to
the channel at the beginning of each clock period. The thermal noise voltage
and current can be observed but Kirchoff's law provides only a second-order
equation. A secure bit is communicated when the actual resistance values at the
sender's side and the receiver's side differ. Then the second order equation
yields the two resistance values but the eavesdropper is unable to determine
the actual locations of the resistors and to find out the state of the sender's
bit. The receiver knows that the sender has the inverse of his bit, similarly
to quantum entanglement. The eavesdropper can decode the message if, for each
bits, she inject current in the wire and measures the voltage change and the
current changes in the two directions. However, in this way she gets discovered
by the very first bit she decodes. Instead of thermal noise, proper external
noise generators should be used when the communication is not aimed to be
stealth.Comment: Physics Letters A, in press; Manuscript featured by Science, vol.
309, p. 2148 (2005, September 30
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