Collaborate Disseminate
How are secret keys shared between receiver and sender, especially when we want to have confidentiality that sender and receiver are using two keys, one for MAC algorithm and one for encryption and decryption?
How do they share these two k… Continue reading how message authentication code share keys?
Given 2 entities, A and B:
A has a public key( x ) and a private key( x* ).
B has a A’s public key hash( let’s call it h(x) ).
A has to prove ownership of x* to B.
How could this be achieved, considering the fact that B is not allowed to s… Continue reading Private key Proof of Ownership [closed]
I need to generate a MAC signature for data on a website, but it’s in a HTML templating system where there’s only a few functions available. The only hashing function available is md5. Ideally, I’d use a real hmac function, but since that’… Continue reading Is md5(data + key) secure if a proper hmac function isn’t available?
I wanted to try new sha3sum so I installed libdigest-sha3-perl on Debian 10. After reading man page I quickly realized that:
sha3sum –algorithm 256 test.txt
produces similar output to sha256sum and that
sha3sum –algorithm 512 test.txt
pr… Continue reading What do algorithms `128000` and `256000` do in `sha3sum`?
Given the following situation: we have sensitive information and want to give a user access to it. At this point the user might not have interacted with our system yet.
We generate a random code that we send to a user to grant him access t… Continue reading Appropriate length and slow, unsalted cryptographic hash function for random codes?
I am looking to hash user passwords to store in a database that will likely reside on a user’s intranet, so I am expecting the database to be classed as open and insecure.
I am using libsodium 1.0.18 to perform the password hashing.
Is thi… Continue reading Good use of libsodium?
I am running Responder on Kali Linux within a client network using the following command
sudo responder -I eth0 -w -r -d
which is capturing many hashes in the environment. Responder is a LLMNR, NBT-NS and MDNS poisoner used for MITM attac… Continue reading Running Responder outputs many hashes per user, how is this possible?
We use a linked hash list for data integrity.
Content is hashed (HMAC-SHA256) and stored in a block that itself is hashed and referenced in the next block:
Simplified example:
…
{
id: "block1",
cId: "A",
cHas… Continue reading How to confirm the last entry of a linked hash list
I tried writing two hashing function and compared it to MurmurHash64A. To my disappointment one was better but maybe 1.5x slower and the other was slightly faster but had more collisions when I truncated the bits to put in my hash table ((… Continue reading Fast string hash function for a specific table size? [migrated]
I would like to compute the MD5 hash of a file
The file is uploaded to my webserver by my clients
The file is uploaded in pieces (called chunks)
The client also sends the md5 hash of the file so that the file integrity could be verified
Th… Continue reading Is MD5 hashing possible by divide and conquer algorithm