Which of the following is NOT a feature or quality of a hash function?
A.
It is mathematically infeasible to derive the original message from the message digest.
B.
The hash function is irreversible.
C.
It is mathematically infeasible for two different messages to produce the same message digest.
D.
The hash function forms a two-way, secure communication.
E.
Encrypted with the sender’s RSA private key, the hash function forms the digital signature.
Explanation:
A hash is a one-way mathematical function that operates to ensure a message’s
integrity. It’s one-way because the process is irreversible. The hash
functions most routinely used are MD4, MD5, and SHA1. A one-way hash
works by taking a variable-length input and putting it through a mathematical
algorithm that produces a fixed-length output called a hash value or
message digest
A one-way hash function is also known by many other names, such as contraction
function, fingerprint, compression function, cryptographic checksum,
message integrity check (MIC), message authentication code (MAC), and
manipulation detection code (MDC).
The purpose of the one-way hash is to determine if the message you
receive has changed from the original message sent. The output of the hash,
or message digest, is combined with the sender’s private key to generate a
digital signature as depicted in Figure below :
