10 Questions
What was the basis for the Data Encryption Standard (DES)?
The IBM Lucifer cipher
What was a controversy surrounding the development of the Data Encryption Standard (DES)?
The NSA was secretly involved and influenced the design
Why was the design process of the Data Encryption Standard (DES) criticized?
It was not open to the public and lacked transparency
What change was made to the Lucifer algorithm during the development of the Data Encryption Standard (DES)?
Subtle changes were made to the algorithm
What was reduced during the development of the Data Encryption Standard (DES)?
The key length
What is the block length of the DES Feistel cipher?
64 bits
How many rounds are used in the DES algorithm?
16 rounds
What is the length of the key used in each round of the DES algorithm?
48 bits
What is the primary security component of the DES algorithm?
S-boxes
What is the mapping performed by each S-box in the DES algorithm?
Maps 6 bits to 4 bits
Study Notes
Data Encryption Standard (DES)
- Developed in the 1970s
- Based on the IBM Lucifer cipher
- Became a U.S. government standard
- Development was controversial due to secret involvement of the National Security Agency (NSA)
- Design process was not open to the public
- Key length was reduced, potentially compromising security
- Subtle changes were made to the original Lucifer algorithm
DES Numerology
- DES is a type of Feistel cipher
- Block length of DES is 64 bits
- Key length of DES is 56 bits
- DES operates for 16 rounds
- In each round, 48 bits of the key are used (subkey)
- Each round of DES is relatively simple for a block cipher
Security of DES
- Security of DES primarily depends on "S-boxes"
- Each S-box in DES maps 6 bits of input to 4 bits of output
This quiz covers the development and controversy surrounding the Data Encryption Standard (DES), a encryption algorithm developed in the 1970s. Learn about the involvement of the NSA and the design process.
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