Random oracle: Difference between revisions

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Adding local short description: "Concept in cryptography", overriding Wikidata description "oracle that responds to every unique query with a (truly) random response chosen uniformly from its output ___domain"
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m Domain separation: Use the common concatenation operator.
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== Domain separation ==
{{main|Domain separation}}
A single oracle may be treated as multiple oracles by pre-pending a fixed bit-string to the beginning of each query (e.g., queries formatted as "1||x" or "0||x" can be considered as calls to two separate random oracles, similarly "00||x", "01||x", "10||x" and "11|x" can be used to represent calls to four separate random oracles). This practice is usually called [[___domain separation]]. ''Oracle cloning'' is the re-use of the once-constructed random oracle within the same proof (this in practice corresponds to the multiple uses of the same [[cryptographic hash]] within one algorithm for different purposes).{{sfn|Bellare|Davis|Günther|2020|p=3}} Oracle cloning with improper ___domain separation breaks security proofs and can lead to successful attacks.{{sfn|Bellare|Davis|Günther|2020|p=4}}
 
== Limitations ==