Tag Archives | security

'Hashed' brown potatoes. Hashing is important on more than just one level (picture by Jamie Davids, CC-BY-2.0)

Hashing passwords: SHA-512 can be stronger than bcrypt (by doing more rounds)

On a server, user passwords are usually stored in a cryptographically secure way, by running the plain passwords through a one-way hashing function and storing its output instead. A good hash function is irreversible. Leaving dictionary attacks aside and by using salts, the only way to find the original input/password which generated its hash, is to simply try all possible […]

Continue Reading 0

Unprivileged Unix Users vs. Untrusted Unix Users. How to harden your server security by confining shell users into a minimal jail

As a server administrator, I recently discovered a severe oversight of mine, one that was so big that I didn’t consciously see it for years. What can Unprivileged Unix Users do on your server? Any so-called “unprivileged Unix users” who have SSH access to a server (be it simply for the purpose of rsync’ing files) is not really “unprivileged” as the […]

Continue Reading 1

Powered by WordPress. Designed by Woo Themes