Your teacher gave you: Public Key: (10142789312725007, 5) which means n = 10142789312725007 e = 5 where n is the modulus and e is the public exponent. In addition, you’re given Private Key: (10142789312725007, 8114231289041741) meaning that d = 8114231289041741 where d is the decryption exponent that should remain secret. You can “break” RSA by … Read more
In most asymmetrical crypto system implementation, the only fact that is ensured is that you cannot find the private key from the public key. The other way round, finding the public key from the private key is trivial in most case. For instance, in RSA, you can create public key from private key with: openssl … Read more
A library is not necessary. Enter crypto. Here’s a janky little module you could use to encrypt/decrypt strings with RSA keys: var crypto = require(“crypto”); var path = require(“path”); var fs = require(“fs”); var encryptStringWithRsaPublicKey = function(toEncrypt, relativeOrAbsolutePathToPublicKey) { var absolutePath = path.resolve(relativeOrAbsolutePathToPublicKey); var publicKey = fs.readFileSync(absolutePath, “utf8”); var buffer = Buffer.from(toEncrypt); var encrypted = … Read more
RSA encryption is only mean for small amounts of data, the amount of data you can encrypt is dependent on the size of the key you are using, for example for 1024 bit RSA keys, and PKCS # 1 V1.5 padding, you can encrypt 117 bytes at most, with a 2048 RSA key, you can … Read more
RSA can only encrypt data blocks that are shorter than the key length so what you normally do is Generate a random key of the correct length required for AES (or similar). Encrypt your data using AES or similar using that key Encrypt the random key using your RSA key Then you publish both the … Read more
GnuPG does multi-key encryption in standard. The following command will encrypt doc.txt using the public key for Alice and the public key for Bob. Alice can decrypt using her private key. Bob can also decrypt using his private key. gpg –encrypt –recipient [email protected] \ –recipient [email protected] doc.txt This feature is detailed in the user guide … Read more
A keystore contains private keys, and the certificates with their corresponding public keys. A truststore contains certificates from other parties that you expect to communicate with, or from Certificate Authorities that you trust to identify other parties.
You can create an RSACryptoServiceProvider from a PEM file using the following class (GetRSAProviderFromPemFile method). Warning: Don’t just copy code from StackOverflow without verification! Especially not crypto code! This code has bugs (see comments). You may want to write and run tests before using this in production (if you really have no better option). I … Read more