LM hash

The algorithm gets almost everything wrong at once. The password is uppercased, truncated or padded to 14 characters and split into two seven-character halves. Each half becomes a DES key used to encrypt the fixed string KGS!@#$%, and the two outputs are concatenated. There is no salt, so the same password always yields the same hash.

The split is the real killer: instead of one 14-character password the attacker faces two independent seven-character problems over an alphabet with no lowercase. Tools like Ophcrack ate them with rainbow tables on an ordinary PC. Windows kept storing LM hashes alongside NTLM for backward compatibility until Vista and Server 2008 finally stopped doing so by default.