Collaborate Disseminate
If I know the password, the salt (supposed salt actually) and the output hash (sha1 format). How can I find the hash creation method ?
I tried basic stuff like
sha1(salt+password)
sha1(password+ salt)
sha1(salt… Continue reading How find the hash creation method knowing password, salt, and resulting hash?
We’re at the start of August, which can only mean one thing. Europe’s hackers and makers are about to converge in a field somewhere for a long weekend of sitting around drinking beer and Club-Mate, eating unhealthy street food, being assaulted by some of the most underground chiptune electronic dance music on the planet, sharing the fruits of their labours with their peers, and gazing lovingly upon other people’s hacks. This year it’s the turn of the Netherlands, for over the first full weekend in August that country will host the SHA2017 outdoor hacker camp in a scouting camp on …read more
When making an IV for AES-256 CBC mode the IV should be random and shouldn’t be able to be guessed.
If I were to use the rand() function in C, seeded with time(NULL) to generate sim random numbers which would then be put thr… Continue reading SHA256 for IV for AES-256 CBC?
I am thinking if using one-way function like SHA-512 is considered to be safe for application on credit card numbers.
The credit card number is 13-19 number with known BIN range (6-8 numbers) and the last one is determined a… Continue reading Is it safe to use SHA-512 to identify credit card?
Why is it big news to find a hash collision like https://news.ycombinator.com/item?id=13713480? I’m not asking about the implications.
It seems like all you’d have to do to find a collision would be to calculate the hash of… Continue reading Why are hash collisions big news?
I’m working with Arduino and hash-based signatures which are signature schemes that use only hash functions. Due to the constraints of an Arduino I was thinking about using SHA1 as the underlying function of my hash-based sig… Continue reading Does still make sense to use SHA1?
How to make a program that calculates a checksum of a file? What is the exact process of calculating a checksum?
Continue reading How can I make a program to verify file integrity?
If you already have SHA1 hashed passwords and you’re trying to migrate to a better password hashing algorithm, is it less secure to just use PBKDF2 to hash the SHA1 hashes you already have instead of migrating users over when… Continue reading Is it insecure to use PBKDF2 on a SHA1 hashed password?
The Problem
In our system users are identified by a composite key. We’d like to devise a scheme to deterministically convert this composite key into a UUID.
Solutions?
The obvious first suggestion would be UUIDv5, however:
It’s based … Continue reading How to reasonably hash a composite key into a UUID?
Say you go onto a website and are downloading a program. Next to the file there is a SHA-1 checksum of the file. You download the program, verify the checksum and find that it is the same as the one on the website – perfect!
… Continue reading What’s wrong with SHA-1 having collisions?
