Mechanism to know what hosts you trust to ssh into. Example: The authenticity of host 'myhost.example.com (172.23.176.251)' can't be established. RSA key fingerprint is SHA256:v5PXX8zCmYY1P01WcEjbEXsj08k4zqPOF3EHqwDwokk. Are you sure you want…

Auth 101

Authentication

Work in progress! Auth scheme An authentication scheme is a method or recipe to pass credentials from a user to an authenticating system. Authorization: <authentication type> <credential as base64> Example: Authorization: Basic…

Keyed hashing vs salted hashing

Hashing

Sha256(myText + saltValue) vs HMAC(myText, myPrivateKey) The main difference is that the salt is not assumed unknown to the attacker, but the key is. An additional difference is that salts are supposed to vary; if you hash three passwords…

Hashing function

Hashing

Hashing is one way, it's irreversible (you cannot "de-hash" a hash to get back the original text). As opposed to encrypting which is revisable (by decrypting). A hash function is any function that can be used to map data of arbitrary size…

Hashtables

Data structure

Java: Hashmap (Hashtable class is deprecated). C#: Dictionary (Hashtable class is deprecated too). /!\ A hash table does not guarantee that the order will remain constant over time. Hashmap in Java final Map<String, String> myLookupTable…