Transcript A Symmetric Key Encryption Using Digital Envelopes Digital

A Symmetric Key Encryption Using Digital
Envelopes
Digital envelopes created to transmit the symmetric key
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Digital envelope:
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Problem:
a technique that uses symmetric encryption for large documents, but
public key encryption to encrypt and send the symmetric key.
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Public key encryption
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Computationally slow, decreased transmission speed, increased processing time
Symmetric key encryption
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Insecure transmission lines
Solution:
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Uses symmetric key encryption to encrypt document
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Uses public key encryption to encrypt and send symmetric
key
Copyright © 2010 Pearson Education, Inc.
Slide 5-1
Creating a Digital Envelope
(key with in key )
•Diplomatic document (message) is Encrypted using a symmetric
Key (which is required by the Receiver to decrypt the document.)
.
•Now symmetric key is encrypted with receiver public key
•The encrypted report and the digital envelope are
sent across the web (internet).
• The receiver first uses his/ her private key to
decrypt the symmetric key , then receiver uses the
Symmetric key to decrypt the report.
Figure 5.10, Page 293
Copyright © 2010 Pearson Education, Inc.
Slide 5-2