Symmetric and Asymmetric Encryption

Which of the following Algorithms belong to symmetric encryption?

• 3DES

• RSA

• RC4

• DES

Assymmetric Encryption: Why can a message encrypted with the Public Key only be decrypted with the receiver's appropriate Private Key?

• Not true, the message can also be decrypted with the Public Key.

• A so called "one way function with back door" is applyed for the encryption.

• The Public Key contains a special function which is used to encrypt the message and which can only be reversed by the appropriate Private Key.

• The encrypted message contains the function for decryption which identifies the Private Key.

In which way does the Combined Encryption combine symmetric and assymmetric encryption?

• First, the message is encrypted with symmetric encryption and aferwards it is encrypted assymmetrically together with the key.

• The secret key is symmetrically transmitted, the message itself assymmetrically.

• First, the message is encrypted with assymmetric encryption and aferwards it is encrypted symmetrically together with the key.

• The secret key is assymmetrically transmitted, the message itself symmetrically.

Which is the largest disadvantage of the symmetric Encryption?

• More complex and therefore more time-consuming calculations.

• Problem of the secure transmission of the Secret Key.

• Less secure encryption function.

• Isn't used any more.

Which of the following statements are correct?

• PGP uses assymmetric encryption.

• In the world wide web, primarly symmetric Encryption is used.

• Symmetric encryption is applied in the transmission of PIN numbers from the EC automat to the server of the bank for example.

• PGP uses combined encryption.