I’m having some trouble understanding the purpose of a salt to a password. It’s my understanding that the primary use is to hamper a rainbow table attack. However, the methods I’ve seen to implement this don’t seem to really make the problem harder. I’ve seen many tutorials suggesting that the salt be used as the … Read more
The hash of infinity in Python has digits matching pi: >>> inf = float(‘inf’) >>> hash(inf) 314159 >>> int(math.pi*1e5) 314159 Is that just a coincidence or is it intentional? 3 Answers 3
One of the basic data structures in Python is the dictionary, which allows one to record “keys” for looking up “values” of any type. Is this implemented internally as a hash table? If not, what is it? 4 Answers 4
Let’s say we have a billion unique images, one megabyte each. We calculate the SHA-256 hash for the contents of each file. The possibility of collision depends on: the number of files the size of the single file How far can we go ignoring this possibility, assuming it is zero? 3 Answers 3
I have an array of hashes, @fathers. a_father = { “father” => “Bob”, “age” => 40 } @fathers << a_father a_father = { “father” => “David”, “age” => 32 } @fathers << a_father a_father = { “father” => “Batman”, “age” => 50 } @fathers << a_father How can I search this array and return an … Read more
Someone told me that he has seen software systems that: retrieve MD5 encrypted passwords from other systems; decrypt the encrypted passwords and store the passwords in the database of the system using the systems own algorithm. Is that possible? I thought that it wasn’t possible / feasible to decrypt MD5 hashes. I know there are … Read more
I am not able to understand what Range / primary key is here in the docs on Working with Tables and Data in DynamoDB How does it work? What do they mean by “unordered hash index on the hash attribute and a sorted range index on the range attribute”? 4 Answers 4
Git’s internal data structure is a tree of data objects, wherein each objects only points to its predecessor. Each data block is hashed. Modifying (bit error or attack) an intermediate block will be noticed when the saved hash and the actual hash deviate. How is this concept different from block chain? Git is not listed … Read more
I’ve always used a proper per-entry salt string when hashing passwords for database storage. For my needs, storing the salt in the DB next to the hashed password has always worked fine. However, some people recommend that the salt be stored separately from the database. Their argument is that if the database is compromised, an … Read more
I’m not sure how password hashing works (will be implementing it later), but need to create database schema now. I’m thinking of limiting passwords to 4-20 characters, but as I understand after encrypting hash string will be of different length. So, how to store these passwords in the database? 10 Answers 10
