I tried searching for this, but could not find a proper answer.
These decryptors work by extracting the encryption key and afterwards using that to decrypt the rest of the files. It requires that you have a file in both the encrypted and unencrypted version and that you know the ransomware kit?
I guess the information from knowing what ransomware kit was used is about knowing what cryptographic method was used to encrypt the files..?
Can someone explain to me how it is possible to extract the key, just from having these files and knowing the encryption algorithm?