Which real-world encryption scheme was successfully attacked using specific known IV vectors, revealing significant vulnerabilities?

FTP operates in a client/server model. An FTP server daemon listens for incoming requests (on TCP port 21) from FTP clients. 

Just as usermod is used to modify user settings and useradd is used to create users, __________ is used to remove users. 

What was a primary consideration in the design of MD4 that also influenced the design of MD5?

In a chosen ciphertext attack, what capability does the adversary have?

What is the primary purpose of the Merkle-Damgård design paradigm in the context of constructing cryptographic hash functions? 

In a Merkle-Damgard design paradigm, a compression function        and updates the internal state of the hash function.

What is a fundamental form of attack to consider when examining an encryption scheme? (Select the best answer choice.)

What is a significant security guarantee of a one-time pad when used correctly? 

In OFB mode with AES or DES, how is the pseudo-random sequence generated?