Which hashing algorithm is stronger than MD5 (Message Digest Algorithm) and produces a much larger output but is not considered an authentication code?

SHA-256 is a hashing algorithm that indeed offers a stronger level of security compared to MD5. Its key characteristics include producing a larger output of 256 bits, in contrast to MD5’s 128 bits, which inherently provides a much wider range of possible hashes. This increased output significantly reduces the probability of hash collisions—instances where two different inputs produce the same hash value.

One of the fundamental principles of hashing algorithms, especially in cryptographic contexts, is to ensure that it's computationally infeasible to reverse the hash back to its original input or to find two different inputs that produce the same hash. SHA-256 achieves this with a more complex structure and a greater number of processing rounds than MD5, enhancing its resistance against various attacks, including brute force and collision attacks.

Therefore, in the context of overall security in cryptographic applications, SHA-256 is favored over MD5 as it meets modern security standards, making it suitable for applications needing higher assurance, yet it is important to note that SHA-256 itself is not specifically an authentication code.