From just reading the linked to article, (I have not read the full paper) it appears that the researcher has conflated the size of the key space with whether or

From just reading the linked to article, (I have not read the full paper) it appears that the researcher has conflated the size of the key space with whether or not the encryption algorithm is secure. Size of the key space only really matters when the only known attacks have a time complexity proportional to the size of the key space, i.e. brute force. If the algorithm itself is horribly broken then it doesn't matter much. For example, a monoalphabetic substitition cipher actually has a rather large key space (26!) but this doesn't really matter.