The title says it all. There are already thousands of online websites where you input a character string, and it would output the MD5 hash (or other) or the password.

I was wondering about the legality of publishing a book with the, lets say, 100 or 1000 most commonly used passwords, together with their hash values.

Note that the book does not endorse/encourage password hacking in any way, it would just be a "hash table" of sorts, combining one kind of information with another.

So would it be legal to publish such a book?

  • 5
    I don't see why not, although this is unlikely to get you anywhere. Any site worth even a little bit salts their passwords, and unless you are talking about an e-book, I'm not sure how I would search 100 or 1000 hashes (and type them in). Given that there are thousands of free password lists and it's trivially easy to generate hash tables from them, I don't see the utility in a "book" for that...
    – Ron Beyer
    May 9, 2021 at 15:31

1 Answer 1


Yes (in most jurisdictions), but why should you?

There might be some interests in publishing the 1,000 most common passwords, e.g. to support security awareness lectures (or to build rainbow tables for nefarious purposes), but anybody who wants to hash them with a specific algorithm can do so easily. It is probably easier to type the passwords from a printed book and to hash them on the computer than it is to type the hashed passwords -- bad passwords would tend to be easy to type.

That being said, computer crime laws are generally lagging behind the state of the art, or they are overly broad, so it might be illegal in some places as a "hacking tool" ...

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    If I was the kind of hacker interested in it, I wouldn't buy it or download it for free. I'd expect rainbow tables with many gigabytes of data to be useful.
    – gnasher729
    May 9, 2021 at 17:20

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