Next Page Public Key Cryptography Unlike symmetric key cryptography, we do not find historical use of public-key cryptography. It is a relatively new concept. Symmetric cryptography was well suited for organizations such as governments, military, and big financial corporations were involved in the classified communication.
Symmetric algorithms require the creation of a key and an initialization vector IV. The key must be kept secret from anyone who should not decrypt your data.
The IV does not have to be secret, but should be changed for each session. Asymmetric algorithms require the creation of a public key and a private key.
The public key can be made public to anyone, while the private key must known only by the party who will decrypt the data encrypted with the public key. This section describes how to generate and manage keys for both symmetric and asymmetric algorithms. Symmetric Keys The symmetric encryption classes supplied by the.
Whenever you create a new instance of one of the managed symmetric cryptographic classes using the default constructor, a new key and IV are automatically created. Anyone that you allow to decrypt your data must possess the same key and IV and use the same algorithm.
Generally, a new key and IV should be created for every session, and neither the key nor IV should be stored for use in a later session. To communicate a symmetric key and IV to a remote party, you would usually encrypt the symmetric key by using asymmetric encryption.
Sending the key across an insecure network without encrypting it is unsafe, because anyone who intercepts the key and IV can then decrypt your data. For more information about exchanging data by using encryption, see Creating a Cryptographic Scheme. Sometimes you might need to generate multiple keys.
In this situation, you can create a new instance of a class that implements a symmetric algorithm and then create a new key and IV by calling the GenerateKey and GenerateIV methods. The following code example illustrates how to create new keys and IVs after a new instance of the asymmetric cryptographic class has been made.
Asymmetric keys can be either stored for use in multiple sessions or generated for one session only. While the public key can be made generally available, the private key should be closely guarded. After a new instance of the class is created, the key information can be extracted using one of two methods: Both methods accept a Boolean value that indicates whether to return only the public key information or to return both the public-key and the private-key information.
Asymmetric private keys should never be stored verbatim or in plain text on the local computer. If you need to store a private key, you should use a key container. For more on how to store a private key in a key container, see How to: Store Asymmetric Keys in a Key Container.
ExportParameters false ; See also.Also known as asymmetric-key encryption, public-key encryption uses two different keys at once -- a combination of a private key and a public key.
The private key is known only to your computer, while the public key is given by your computer to any computer that wants to communicate securely with it. The Public Key is what its name suggests - Public. It is made available to everyone via a publicly accessible repository or directory.
On the other hand, the Private Key must remain confidential to its respective owner. No. The public key is not used to decrypt, but to encrypt. You decrypt with your private key. That way, only you can decrypt the message.. Usually though, private-public key encryption is too expensive to encrypt data with.
The elementary working of Public Key Cryptography is best explained with an example. The working below covers the making of simple keys and the encryption and decryption of a sample of plain text.
By necessity, the example is greatly simplified. A public key is available to all, and is used to. Encryption algorithms which use the same key for both encryption and decryption are known as symmetric key algorithms.
A newer class of "public key" cryptographic algorithms was invented in . As I’m working on a product that will make heavy use of encryption, I’ve found myself trying to explain public-key cryptography to friends more than once lately.
To my surprise, anything.