Hash-based signature algorithms are promising candidates for securing communication in the age of quantum computers. SPHINCS+ is an example of such a stateless signature algorithm that gained popularity from the recent„Post-Quantum Cryptography Standardisation Competition”. A major downside of hash-based signature algorithms like SPHINCS+ is the size of the signature itself, which is magnitudes larger than what other algorithms provide. However, there are recent alternatives to SPHINCS+ that are being developed to reduce the downsides while still maintaining the benefits of the hash-based approach. For example, two such variants are Giza and Manticore. In this project, you will work with experts on this subject to get familiar with these alternatives. Your task is to analyse them cryptographically and to implement prototypes of these algorithms.