E91 may refer to:
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E91 protocol
Quantum key distribution (QKD) is a secure communication method which implements a cryptographic protocol involving components of quantum mechanics. It enables two parties to produce a shared random secret key known only to them, which can then ...
, a protocol of Quantum Cryptography
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E91, a car of the BMW 3 Series
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King's Indian Defense
The King's Indian Defence is a common chess opening. It is defined by the following moves:
:1. d4 Nf6
:2. c4 g6
Black intends to follow up with 3...Bg7 and 4...d6 (the Grünfeld Defence arises when Black plays 3...d5 instead, and is consid ...
, Encyclopaedia of Chess Openings code
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European route E91, one of the many routes in the
European route
The international E-road network is a numbering system for roads in Europe developed by the United Nations Economic Commission for Europe (UNECE). The network is numbered from E1 up and its roads cross national borders. It also reaches Centr ...
network.
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Minami-Hanna Road and Yamatotakada Bypass, route E91 in Japan.
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