Instruction Encryption/Decryption Arrangement and Method with Iterative Encryption/Decryption Key Update

An instruction encryption arrangement, comprising:

• an input interface configured to receive a plain instruction;
• an encryption key updater configured to output an encryption key;
• and
• an instruction encrypter comprising a first input connected to the input interface and a second input connected to the encryption key updater, and configured to encrypt the plain instruction using the encryption key and to provide an encrypted instruction;
• wherein the encryption key updater is further configured to update the encryption key using at least one of the plain instruction and the encrypted instruction.

An instruction decryption arrangement, comprising:

• means for receiving an encrypted instruction;
• means for updating a decryption key;
• and
• means for decrypting the encrypted instruction using the decryption key and for providing a corresponding decrypted instruction;
• wherein the means for updating the decryption key is configured to update the decryption key using at least one of the encrypted instruction and the decrypted instruction.

A method for decrypting instructions for a computing unit, the method comprising:

• receiving an encrypted instruction;
• obtaining a decryption key;
• combining the decryption key with the encrypted instruction for generating a decrypted instruction;
• and
• updating the decryption key by using at least one of the encrypted instruction and the decrypted instruction.

A computer readable digital storage medium having stored thereon a computer program having a program code for performing, when running on a computer, a method for decrypting instructions for a computing unit, the method comprising:

• receiving an encrypted instruction;
• obtaining a decryption key;
• combining the decryption key with the encrypted instruction for generating a decrypted instruction;
• and
• updating the decryption key by using at least one of the encrypted instruction and the decrypted instruction.

A method for encrypting instructions for a computing unit, the method comprising:

• receiving a plain instruction;
• obtaining an encryption key;
• combining the encryption key with the plain instruction for generating an encrypted instruction;
• and
• updating the encryption key by using at least one of the plain instruction and the encrypted instruction.

A computer readable digital storage medium having stored thereon a computer program having a program code for performing, when running on a computer, a method for encrypting instructions for a computing unit, the method comprising:

• receiving a plain instruction;
• obtaining an encryption key;
• combining the encryption key with the plain instruction for generating an encrypted instruction;
• and
• updating the encryption key by using at least one of the plain instruction and the encrypted instruction.