24 lines
746 B
ReStructuredText
24 lines
746 B
ReStructuredText
Attributes of an 8-block cipher
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###############################
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:date: 2012-02-13 00:50
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:author: Russell Ballestrini
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:tags: Security
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:slug: attributes-of-an-8-block-cipher
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:status: published
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**Consider an 8-block cipher and answer the following:**
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How many possible input blocks does this cipher have?
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How many possible mappings are there?
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If we view each mapping as a key, then how many possible keys does this cipher have?
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To find the input blocks of this cipher we raise 2 to the 8th power. 2^8 = 256 possible inputs.
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To find the number of possible mappings we take the 256 input blocks and
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find it's factorial. There are 256! possible mappings.
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We can view each of these mappings as a key, so this cipher has 256! keys.
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.. contents::
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