Let’s call PP your Potential Prime. (1) Choose a random number a less than PP. (2) Calculate a^(p-1)/2 mod PP. (3) If a^(PP-1)/2 /= 1 or -1 (mod PP), then PP is not prime. (4) If a^(PP-1)/2 = 1 or -1 (mod PP), then the probability that PP is not prime is less than 50%. … Read more
In Objective C this can be done as follows: -(NSString *)decode:(NSString *)input { NSArray<NSString *> *components = [input componentsSeparatedByString:@”-“]; NSMutableString *output = [[NSMutableString alloc] init]; for (NSString *component in components) { if (component.length == 0) { continue; } char charValue = (char) [component intValue]; [output appendFormat:@”%c”, charValue + (‘a’ – 1)]; } return [NSString stringWithString:output]; … Read more
Not sure I get your question right but my bet is you’re asking how to convert between ASCII and number representation of characters. Encoding/Decoding has nothing to do with RSA. You just use dynamic range shift. As the alphabet is in increasing order in ASCII so the only thing left is to offset the a … Read more
I think you miss some code here, cause that is not valid: // Read the decrypted bytes from the decrypting stream 2 solved Decrypt function is not working c# [closed]
If the encryption method is an accepted standard method such as AES and the key is good it is not possible to find the key given the plain and encrypted data. If the encryption method is trivial such as Caeser Cipher then it can be found. If the key is trivial such as “password” or … Read more
There is a quite simple answer to how to encrypt files. This script uses the XOR encryption to encrypt files. Encrypt the file a second time to decrypt it. #include <iostream> #include <fstream> #include <string> using namespace std; void encrypt (string &key,string &data){ float percent; for (int i = 0;i < data.size();i++){ percent = (100*i)/key.size(); … Read more
It seems the text is encrypted with the NULL encryption algorithm described in RFC 2410. If I run it through the accompanying decryption algorithm, it decrypts properly without error and gives the following plain text: OH0fRX0gOHZgOH0tOH4fRX8tOr0gOHZgOH0tOH4fOrZgOH0fRX8tOH4gOHZgOH0tOr4gRX8tOr4fRX0gOHZfOH4fRX4fOr0tOrZgOr4tObZgRX4fOr4tOrZeRX4fOrZfRX0fOH4tOH0gRX0fRX0fOrZeRX4gOH4tOr4gRX0gOr4tOH0fOrZfOH4fRX4tOr0fOH4gRX8tOr4fRX4fOHZgOr4fRX0gRX4fRX0tObZgRX4fOr4tOrZeRX4fOH4tOr0fOrZfOHZgOH4tObZgOr4fRX4tOr0fOrZgOH0tOr0gRX8tOHZgOH0tObZgOr0fRX4gOr4tOr0tOr4tOH0tObZgOr0gRX0gOHZfOr0tOr0fRX8tOr0gOrZgOH0tOr4tOH4tOHZfOr4tOr0fOH4gRX4gOr0fOrZfOH4gOr4tOr4gOrZfOH4fRX4gRX0gOrZgOH0fOr4tObZgOrZgOr0fRX4gOr4tOH4fOr4gRX0fOH4tOr0fRX4gOH0tOr4gOrZgOr4fOr0tOH0gOr4tOH0gOH0tOr4fOH0tOH0gOr4tOr0fOH4fRX4gOr0fOrZfOr0fRX4gOr4tOr0tOH0fRX4fOr0gRX4gOr0fOrZgOr4fOr0tOH4fOr4gRX0fOr4fOHZgOr4fOr0tOH4fOr4gRX4gOr0fOrZgRX4gOHZgOr4tOr4fRX0fOH0tOr4tOH4fOrZfOr4gOHZgOr4fRX4fOr0gRX4gOH0tOr0gOrZfOrZfOr4tOH4fOrZgOH4fRX0fOr4tOr4fOH0tOr4gRX0gOrZgOr0fRX4fOH0gRX0gOH0fRX0gOr0tOH4fRX0 The plain text does not make much sense to me, however. But that’s the fundamental problem with data: There … Read more
Hashing is a one way process and Encryption is 2 way process. What I mean by this is , when we use a plain text and encrypt it to get a cipher text, we can again get the plain text from the cipher text. but that is not the case for hashing. You can never … Read more
A central principle of a hash is that it is one way, as you have read. Since you want to be able to perform a two way conversion between your data and a secured version you need to use encryption, which is specifically designed to both encrypt and then later decrypt the data in question. … Read more
Zip it and password protect the entry 🙂 full compatibility with any PC and decent security 🙂 (Zip ueses AES to pretect it’s entries). solved lock text files with passwords [closed]
Try this: with open(‘file.out’, ‘w’) as output: for n in xrange(100000000): s = “{0:08d}”.format(n) output.write(s[:2] + ‘-‘ + s[2:] + ‘\n’) … But be aware that that’s a lot of combinations, it’s possible that you’ll run out of memory, and if not anyway the resulting file will be huge and the program will take a … Read more
(As suggested, I’ve replaced my previous salt generation method with something that should be more secure) To generate a random salt: public static string GenerateRandomSalt(RNGCryptoServiceProvider rng, int size) { var bytes = new Byte[size]; rng.GetBytes(bytes); return Convert.ToBase64String(bytes); } var rng = new RNGCryptoServiceProvider(); var salt1 = GenerateRandomSalt(rng, 16); var salt2 = GenerateRandomSalt(rng, 16); // etc. … Read more
There is “Post-Quantum Cryptography” published by Daniel J. Bernstein. The book is more of a general overview and doesn’t go that far into details. It contains sections about lattice based, hash based and code based cryptography. Shor’s algorithm as well as discrete logarithm aren’t handled in depth, but there is a general overview. I think … Read more