It is very useful to download bib entries from DBLP but the entries contains some information I dont care about, and more importantly, the cite keys that are not usable. A nice tool to clean up bib files, and also recompute entries keys is BibTool. The configuration file for bibtool is a bit of a dark art, but here is my configuration file – it removes some of DBLP redundant files, and uses authors last names initials for first part of the key, initials of words in title as first part of the key, and then the year.
To clean bib file using bibtool, invoke:
bibtool -r bibtool_config.rsc -i old_file.bib -o out.bib