No. MD5 is not encryption (though it may be used as part of some encryption algorithms), it is a one way hash function. Much of the original data is actually “lost” as part of the transformation. Think about this: An MD5 is always 128 bits long. That means that there are 2128 possible MD5 hashes. … Read more
Share the password (a char[]) and salt (a byte[]—8 bytes selected by a SecureRandom makes a good salt—which doesn’t need to be kept secret) with the recipient out-of-band. Then to derive a good key from this information: /* Derive the key, given password and salt. */ SecretKeyFactory factory = SecretKeyFactory.getInstance(“PBKDF2WithHmacSHA256”); KeySpec spec = new PBEKeySpec(password, … Read more
EDIT 2013-Oct: Although I’ve edited this answer over time to address shortcomings, please see jbtule’s answer for a more robust, informed solution. https://stackoverflow.com/a/10366194/188474 Original Answer: Here’s a working example derived from the “RijndaelManaged Class” documentation and the MCTS Training Kit. EDIT 2012-April: This answer was edited to pre-pend the IV per jbtule’s suggestion and as … Read more
You could use something like the following algorithm to accomplish this: // Our input string. String input = “I love fish”; // Contains the “encrypted” output string. StringBuilder encrypted = new StringBuilder(); // Process each character in the input string. for (char c : input.toCharArray()) { if (Character.toLowerCase(c) != ‘a’ && Character.isLetter(c)) { // If … Read more
Replace : if (y>ekeylen) { y=0; } by if (y>=ekeylen) { y=0; }
It will be impossible to determine an encryption algorithm without source code or some amount of reverse engineering. The old encryption uses AES256 in CBC mode, but that is obvious. If you don’t have access to the new code, then you probably shouldn’t be attempting this anyways..
You don’t have to use dictionaries… There is an easier way, using string module: from string import printable, maketrans def caesar(string, key): shifted_alphabet = printable[key:] + printable[:key] table = maketrans(printable, shifted_alphabet) return string.translate(table) string = raw_input(“Enter something> “) #input for python 3 while 1: try: key = int(raw_input(“Enter key (0-25): “)) except: print “Key should … Read more
Python has to read the library to run it, and to read it correctly, it must be decrypted. Otherwise how do you expect python to be able to run encrypted code? If you distribute an encrypted library, you have to add code to decrypt the library first before importing it. Otherwise there is no way … Read more
Hashes are uni-directional, so no. http://en.wikipedia.org/wiki/Hash_function