Eccouncil 212-81 Exam Dumps

Encrypting with RSA

https://en.wikipedia.org/wiki/RSA_(cryptosystem)

RSA Encrypting a message m (number) with the public key (n, e) is calculated:

M' := m^e %n

Incorrect answers:

Decrypting with RSA:

M'' := m^d %n

Generation Mersenne primes:

Mn = 2^n - 1

Encrypting with Elliptic Curve (EC):

y^2 = x^3 + ax + b

Reversible

https://en.wikipedia.org/wiki/Hash_function

Hash functions are not reversible.

Incorrect answers:

Fixed length output and Variable length input. Hash function receive variable length input and produce fixed length output

Few collisions. Every hash function with more inputs than outputs will necessarily have collisions

lbs

https://en.wikipedia.org/wiki/Bit_numbering#:~:text=In%20computing%2C%20the%20least%20significant,number%20is%20even%20or%20odd.

The least significant bit (LSB) is the bit position in a binary integer giving the units value, that is, determining whether the number is even or odd. The LSB is sometimes referred to as the low-order bit or right-most bit, due to the convention in positional notation of writing less significant digits further to the right. It is analogous to the least significant digit of a decimal integer, which is the digit in the ones (right-most) position.

Skipjack

https://en.wikipedia.org/wiki/Skipjack_(cipher)

Skipjack uses an 80-bit key to encrypt or decrypt 64-bit data blocks. It is an unbalanced Feistel network with 32 rounds.

Incorrect answers:

Twofish - is a symmetric key block cipher with a block size of 128 bits and key sizes up to 256 bits. It was one of the five finalists of the Advanced Encryption Standard contest, but it was not selected for standardization. Twofish is related to the earlier block cipher Blowfish.

AES - For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits.

DES - Data Encryption Standard is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for applications, it has been highly influential in the advancement of cryptography.