3i Infotech Placement: Sample Questions 946 - 947 of 1245
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Question 946
Explanation
- International Data Encryption Algorithm.
- Uses a block cipher with a 128-bit key.
- Considered among the best publicly known algorithms.
- Patented in the United State and in most of the European countries.
- Provides good privacy
- Incorporated after the original cipher used was v1.0, BassOmatic.
- Entirely avoids use of any lookup tables or S-boxes.
- Divides data into four quarters, each 16 bits long- combination of two 16 bit values produces a 16-bit result through addition, XOR and multiplication.
Question 947
Explanation
Definition:
- Domain-key normal form (DKNF) is a normal form, it is used in database normalization
- Requires no constraints other than domain constraints and key constraints.
- Example is Boyce-Codd normal form (BCNF) , fourth normal form, and fifth normal form
- Avoids having general constraints in the database.
- All database constraints simply check all attribute values in a tuple form are of the appropriate domain and that every key constraint is enforced.
- While the domain-key normal form eliminates the problems found in most databases, it tends to be the most costly normal form to achieve.