Thanks for your answer. Could you explain me how my method is not secure assuming:

    1. The pass is long
    2. The preimage is known

If nobody can find `sha1(knownpart|hiddenpart)`, how is my method insecure?

Is the problem linked to sha1 or if I use any other hash this method also fail?

I presume the _only_ method you advocate for is to have a lot of different passwords for each website is to store randomly generated password inside a keychain system. Could you enlighten me? How do you deal with your own password?

Thanks.

edit: it seems we reached the max depth. Thank you Dmitry!