Coding Weak Encryption in C and Breaking It

My encryption tool coded in C uses a weak hashing algorithm to hash the input key. Let me show you how easily weak hashing algorithms can be exploited using hash collisions. A hash collision occurs when two different inputs produce the same hash value. Since many encryption algorithms first hash the input key, they are all subject to hash collision exploits. Always use cryptographically secure hashes!

[HirschDaniel]

Please note that files encrypted using the encryption code are still safe. At least as safe as 32 bit (size of int) encryption gets. The reason it is safe is that the hash is NOT stored with the encrypted file. Without knowing the hash, it is impossible for an attacker to generate a hash collision. I just demonstrated what would happen IF an attacker knew the hash (e.g. in the case of a user credentials database, which an attacker gained access to).