For the experts: What encryption algo is this?

Hey guys,

Sorry for being so selfish with my first post, but I have been stuck on this for a good 20 hours and I have no idea where to ask for help.

I am struggling to figure out what this type of encryption algorithm is:

Key [Hex] = d17f1eb045
Encrypted Message [HEX] = 21fe382d153cb673f37bbdc482e3329fea5bc1c256aa698e6b98618d3c57ada1808e73913774bc50d25d79c4d7f9f837e91a5c75d2f480f048fe008436457ba6832d74663c7d594ce613ca80e10745f9c7c57f17ce259f513999abb2b21acdb2c893fe730cc420

Let me know