Defining asymmetric encryption
In the .NET framework, one can find some different types of cryptography. These include symmetric and asymmetric encryption, digital signatures, and even hashing. You need to know what encrypting data with a public-key and decrypting data with a public-key means. This is quite simple and it means exactly asymmetric encryption.
How to encrypt data using asymmetric encryption
Asymmetric encryption can also be called public-key encryption. This type of encryption is better than symmetric encryption because it requires that both the encryptor and the decryptor to know a so called shared secret. Asymmetric encryption is relying on key pairs (only one public key and only one private key). While the public key can be shared at any time (attackers cannot easily abuse them), the messages can only be decrypted by using the private key. In short words, messages can be sent by virtually anyone, but they can be decrypted by only one individual.
The actual process:
- The exchange of public keys between the server and the client. If only one side has to be encrypted, the peer that receives the encrypted message must provide a valid public key.
- After both parties receive the public key, communications are starting to be encrypted using the recipient’s key.
- Messages can only be decrypted by the receiver as only he has the private key.
Advantages and disadvantages when using asymmetric encryption
Although symmetric encryption is faster than asymetric encryption, the last is more secure. The programmer chooses what to use and must consider both speed and security. Large amounts of data are difficult to encrypt by using asymmetric key encryption due to the performance overhead. One other major problem with this type of encryption is key management. In many organizations, a public key infrastructure (abbreviated PKI) is implemented and used for revoking, distributing, and managing certificates.
By combining .NET and C# asymmetric encryption with .NET and C# symmetric encryption, a programmer can achieve greater efficiency then by using only one type of encryption.
Key Exam Points
- Make sure you understand how asymmetric encryption works
- Study implementations of asymetric encryption in .NET, C#, etc
- Do some excercises on your own to make sure you master this technique
Related Terms
This article is based on the 2nd edition of the Microsoft .Net Framework Application Training Kit with the purpose to help 70-536 Exam takers to succeed. I constantly look for ways to improve the content. Please leave a comment about this article or drop me a message if you would like to see changes for this site.
