Method and device for protecting digital data by double re-encryption

A method for protecting decrypted digital data from illegitimate use, comprising:

• encrypting said decrypted digital data using an unchangeable key to produce unchangeable key re-encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during said encrypting of said decrypted digital data;
• encrypting said unchangeable key re-encrypted digital data using a changeable key to produce unchangeable-changeable key double re-encrypted digital data to be stored, copied and/or transferred;
• decrypting said copied, stored and/or transferred unchangeable-changeable keys double re-encrypted digital data using said changeable key to said unchangeable key re-encrypted digital data;
• and
• decrypting said unchangeable key re-encrypted digital data using said unchangeable key to said decrypted digital data.

An apparatus for protecting decrypted digital data from illegitimate use, said apparatus comprising:

• a changeable key encryption unit capable of encrypting said decrypted digital data using a changeable key to produce changeable key re-encrypted digital data;
• an unchangeable key encryption unit capable of encrypting said changeable key re-encrypted digital data using an unchangeable key to produce changeable-unchangeable keys double re-encrypted digital data to be stored, copied and/or transferred, wherein said unchangeable key is capable of being operationally unchangeable at least during production of said changeable-unchangeable keys double re-encrypted digital data;
• an unchangeable key decryption unit capable of decrypting said copied, stored and/or transferred changeable-unchangeable keys double re-encrypted digital data using said unchangeable key to said changeable key re-encrypted digital data;
• and
• a changeable key decryption unit capable of decrypting said changeable key re-encrypted digital data using said changeable key to said decrypted digital data.

An apparatus for protecting decrypted digital data from illegitimate use, said apparatus comprising:

• an unchangeable key encryption unit capable of encrypting said decrypted digital data using an unchangeable key to produce unchangeable key re-encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during production of said unchangeable key re-encrypted digital data;
• a changeable key encryption unit capable of encrypting said unchangeable key re-encrypted digital data using a changeable key to produce changeable-unchangeable keys double re-encrypted digital data to be stored, copied and/or transferred;
• a changeable key decryption unit capable of decrypting said copied, stored and/or transferred
• changeable-unchangeable keys double re-encrypted digital data using said changeable key to said unchangeable key re-encrypted digital data;
• and
• an unchangeable key decryption unit capable of decrypting said unchangeable key re-encrypted digital data using said unchangeable key to said decrypted digital data.

A method for protecting decrypted digital data from illegitimate use, said decrypted digital data being decrypted from digital data encrypted using a first changeable key, said method comprising:

• encrypting said decrypted digital data using a second changeable key to produce second changeable key re-encrypted digital data;
• encrypting said second changeable key re-encrypted digital data using an unchangeable key to produce unchangeable second changeable keys double re-encrypted digital data to be stored, wherein said unchangeable key is capable of being operationally unchangeable at least during said encrypting of said second changeable key re-encrypted digital data;
• decrypting said stored unchangeable-second changeable keys double re-encrypted digital data using said unchangeable key to said second changeable key re-encrypted digital data;
• encrypting said second changeable key re-encrypted digital data using a third changeable key to produce third changeable-second changeable keys double re-encrypted digital data to be copied and/or transferred;
• decrypting said copied and/or transferred third changeable-second changeable keys double re-encrypted digital data using said third changeable key to said second changeable key re-encrypted digital data;
• and
• decrypting said second changeable key re-encrypted digital data using said second changeable key to said decrypted digital data.

A method for protecting decrypted digital data from illegitimate use, said decrypted digital data being decrypted from digital data encrypted using a first changeable key, said method comprising:

• encrypting said decrypted digital data using an unchangeable key to produce unchangeable key re-encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during said encrypting of said decrypted digital data, and encrypting said unchangeable key re-encrypted digital data using a second changeable key to produce second changeable-unchangeable keys double re-encrypted digital data to be stored;
• decrypting said stored second changeable-unchangeable keys double re-encrypted digital data using said second changeable key to said unchangeable key re-encrypted digital data;
• decrypting said unchangeable key re-encrypted digital data using said unchangeable key to said decrypted digital data;
• encrypting said decrypted digital data using a third changeable key to produce third changeable key re-encrypted digital data, and encrypting said third changeable key re-encrypted digital data using said second changeable key to produce second changeable-third changeable keys double re-encrypted digital data to be copied and/or transferred;
• decrypting said copied and/or transferred second changeable-third changeable keys double re-encrypted digital data using said second changeable key to said third changeable key re-encrypted digital data;
• and
• decrypting said third changeable key re-encrypted digital data using said third changeable key to said decrypted digital data.

An apparatus for protecting decrypted digital data from illegitimate use, said decrypted digital data being decrypted from digital data encrypted using a first changeable key, said apparatus comprising:

• a second changeable key encryption unit capable of encrypting said decrypted digital data using a second changeable key to produce second changeable key re-encrypted digital data;
• an unchangeable key encryption unit capable of encrypting said second changeable key re-encrypted digital data using an unchangeable key to produce unchangeable-second changeable keys double re-encrypted digital data to be stored, wherein said unchangeable key is capable of being operationally unchangeable at least during production of said unchangeable-second changeable keys double re-encrypted digital data;
• an unchangeable key decryption unit capable of decrypting said stored unchangeable-second changeable keys double re-encrypted digital data using said unchangeable key to said second changeable key re-encrypted digital data;
• a third changeable key encryption unit capable of encrypting said second changeable key re-encrypted digital data using a third changeable key to produce third changeable-second changeable keys double re-encrypted digital data to be copied and/or transferred;
• a third changeable key decryption unit capable of decrypting said copied and/or transferred changeable-second changeable keys double re-encrypted digital data using said third changeable key to said second changeable key re-encrypted digital data;
• and
• a second changeable key decryption unit capable of decrypting said second changeable key re-encrypted digital data using said second changeable key to decrypted digital data.

An apparatus for protecting decrypted digital data from illegitimate use, said decrypted digital data being decrypted from digital data encrypted using a first changeable key, said apparatus comprising:

• an unchangeable key encryption unit capable of encrypting said decrypted digital data using an unchangeable key to produce unchangeable key re-encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during production of said unchangeable key re-encrypted digital data, and a second changeable key encryption unit capable of encrypting said unchangeable key re-encrypted digital data using a second changeable key to produce second changeable-unchangeable key double re-encrypted digital data to be stored;
• a second changeable key decryption unit capable of decrypting said stored second changeable-unchangeable keys double re-encrypted digital data using said second changeable key to unchangeable key re-encrypted digital data, and an unchangeable key decryption unit capable of decrypting said unchangeable key re-encrypted digital data using said unchangeable key to decrypted digital data;
• a third changeable key encryption unit capable of encrypting said decrypted digital data using a third changeable key to produce third changeable key re-encrypted digital data, and a second changeable key encryption unit capable of encrypting said third changeable key re-encrypted digital data using said second changeable key to produce second changeable-third changeable keys double re-encrypted digital data to be copied and/or transferred;
• and a second changeable key decryption unit capable of decrypting said copied and/or transferred second changeable-third changeable keys double re-encrypted digital data using said second changeable key to said third changeable key re-encrypted digital data, and a third changeable key decryption unit capable of decrypting said third changeable key re-encrypted digital data using said third changeable key to decrypted digital data.

A method for protecting digital data from illegitimate use, said method comprising:

• determining whether said digital data is subject to be protected or not;
• encrypting said digital data, determined to be protected, using an unchangeable key to produce unchangeable key encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during said encrypting of said digital data;
• storing, copying and/or transferring said unchangeable key encrypted digital data;
• decrypting said stored, copied and/or transferred unchangeable key encrypted digital data using said unchangeable key to decrypted digital data;
• and
• utilizing said stored, copied and/or transferred unchangeable key encrypted digital data and said decrypted digital data.

An apparatus for protecting digital data from illegitimate use, said apparatus comprising:

• determining means for determining whether said digital data is subject to be protected or not;
• means for encrypting said digital data, determined being subject to be protected, using an unchangeable key to produce unchangeable key encrypted digital data, wherein said unchangeable key is capable of being operationally unchangeable at least during said encrypting of said digital data;
• means for storing, copying and/or transferring said unchangeable key encrypted digital data;
• means for decrypting said stored, copied and/or transferred unchangeable key encrypted digital data to said decrypted digital data;
• and
• means for utilizing said stored, copied and/or transferred unchangeable key encrypted digital data and said decrypted digital data.