1. md5
128bit hash function. Inverse or collision cannot be find in reasonable time, however there are useful website to bruteforce(Search on google)
2. sha1
160bit hash function. It is known as safer than md5. Same as md5, easily find bruteforcing website.
3. DES based hash algorithm
DES is block cipher. Although block cipher based hash algorithm is also safe, it is slower than md5 or sha1. So not that usually used.