Question

Increasing the key length is one way to increase security of an encryption algorithm against the brute-force type of attack. DES uses 56-bit key, which is not secure, given the modern computing power. Assume that 56-bit key was just sufficient in 1979 when DES was standardized, and assume that the hardware performance improves about 100% (i.e., doubles) every two years, then how many bits of a DES key would just suffice in the year 2020 ? Your Answer:

Answer 1

The recommended key length for encryption algorithms is at least 128 bits. Given the hardware performance improvement, a DES key of 117,964,800 bits would suffice in 2020.

Step-by-step explanation:

The cryptography experts generally agree on the recommendation of using a key length of at least 128 bits for modern encryption algorithms to ensure security against brute-force attacks.

Considering the hardware performance improvement of about 100% every two years, we can estimate the number of bits that would suffice for encryption in the year 2020.

Since hardware performance doubles every two years, we can approximate that it would double 20 times from 1979 to 2020 (a period of 41 years). So, the number of bits required for a DES key to suffice in 2020 can be calculated as:

1. 56 bits * (2^20)
2. 56 bits * 2,097,152
3. 117,964,800 bits

Therefore, it would be recommended to use a 117,964,800-bit key for DES in the year 2020 to ensure sufficient security against brute-force attacks.