Method for encrypting and embedding information in a video program

• US 5,581,614 A
• Filed: 01/18/1994
• Issued: 12/03/1996
• Est. Priority Date: 08/19/1991
• Status: Expired due to Fees

• Current Assignee: Rovi Guides, Inc. (Adeia Inc.)
• Original Assignee: Index Systems Incorporated (Adeia Inc.)
• Inventors: Ng, Yee K., Mankovitz, Roy J.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/183,602
• Time in Patent Office: 1,050 Days
• Field of Search: 380/3, 380/5, 380/21, 380/20
• US Class Current: 380/239
• CPC Class Codes: G11B 15/00 Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function driving or guiding heads G11B3/00 - G11B7/00, G11B21/00
• CPC Class Codes: G11B 15/02 Control of operating function, e.g. switching from recording to reproducing
• CPC Class Codes: G11B 15/023 remotely controlled
• CPC Class Codes: G11B 15/026 by using processor, e.g. microcomputer
• CPC Class Codes: G11B 15/07 on containers
• CPC Class Codes: G11B 15/087 by sensing recorded signals
• CPC Class Codes: G11B 15/1816 Programmed access in sequence to indexed parts of operating tapes cooperating with rotating heads see provisional also G11B15/005
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/41 Flat as opposed to hierarchical combination, e.g. library of tapes or discs, CD changer, or groups of record carriers that together store one title
• CPC Class Codes: G11B 2220/65 wherein solid state memory is used for storing indexing information or metadata
• CPC Class Codes: G11B 2220/655 Memory in cassette [MIC]
• CPC Class Codes: G11B 2220/80 Indexing information stored in optical or magnetic or other strip attached to cassette or disc, e.g. barcodes attached to a recording medium
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/91 Helical scan format, wherein tracks are slightly tilted with respect to tape direction, e.g. VHS, DAT, DVC, AIT or exabyte
• CPC Class Codes: G11B 23/08714 Auxiliary features sensing such features G11B15/06
• CPC Class Codes: G11B 23/30 with provision for auxiliary signals
• CPC Class Codes: G11B 23/36 Signals on record carriers or on containers and recorded by the same method as the main recording
• CPC Class Codes: G11B 27/002 Programmed access in sequence to a plurality of record carriers or indexed parts, e.g. tracks, thereof, e.g. for editing; transfer of record carriers from magazine G11B15/68, G11B17/10; G11B17/22
• CPC Class Codes: G11B 27/024 on tapes G11B27/028, G11B27/029 take precedence
• CPC Class Codes: G11B 27/029 Insert-editing
• CPC Class Codes: G11B 27/107 : of operating tapes
• CPC Class Codes: G11B 27/11 : by using information not detectable on the record carrier
• CPC Class Codes: G11B 27/13 : the information being derived from movement of the record carrier, e.g. using tachometer
• CPC Class Codes: G11B 27/28 : by using information signals recorded by the same method as the main recording G11B27/22 takes precedence
• CPC Class Codes: G11B 27/3054 : Vertical Interval Time code [VITC]
• CPC Class Codes: G11B 27/309 : Table of contents
• CPC Class Codes: G11B 27/324 : Duty cycle modulation of control pulses, e.g. VHS-CTL-coding systems, RAPID-time code, VASS- or VISS-cue signals
• CPC Class Codes: G11B 27/328 : on a tape [TTOC]
• CPC Class Codes: G11B 27/34 : Indicating arrangements indicating means incorporated in magazine or cassette G11B23/046 and G11B23/0875; indicating measured values in general G01D
• CPC Class Codes: G11B 27/36 : Monitoring, i.e. supervising the progress of recording or reproducing for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06
• CPC Class Codes: G11B 31/00 : Arrangements for the associated working of recording or reproducing apparatus with related apparatus with cameras or projectors G03B31/00 ; recording/reproducing of music for electrophonic musical instruments G10H1/0033; automatic arrangements for answering calls or for recording messages for absent subscribers H04M1/64; telephonic communication systems adapted for combination with dictation recording and playback systems H04M11/10; connection of TV recorder with other related apparatus, e.g. TV camera or receiver, in which the TV signal is significantly involved H04N, e.g. H04N23/00, H04N5/765; combination of radio or TV with other apparatus, e.g. with vehicles H05K11/00
• CPC Class Codes: G11B 33/10 : Indicating arrangements; Warning arrangements G11B15/04, G11B19/04, G11B27/34, G11B27/36 take precedence
• CPC Class Codes: G11B 5/0086 : using cyclically driven heads providing segmented tracks
• CPC Class Codes: G11B 5/86 : Re-recording, i.e. transcribing information from one magnetisable record carrier on to one or more similar or dissimilar record carriers by varying the order of the information G11B27/029, G11B27/036
• CPC Class Codes: H04H 20/28 : Arrangements for simultaneous broadcast of plural pieces of information
• CPC Class Codes: H04H 60/23 : using cryptography, e.g. encryption, authentication, key distribution
• CPC Class Codes: H04N 21/2351 : involving encryption of additional data arrangements using cryptography for the use of broadcast information or broadcast-related information H04H60/23
• CPC Class Codes: H04N 21/26606 : for generating or managing entitlement messages, e.g. Entitlement Control Message [ECM] or Entitlement Management Message [EMM] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 5/45 : Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 5/765 : Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/775 : between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/7755 : the recorder being connected to, or coupled with, the antenna of the television receiver
• CPC Class Codes: H04N 5/782 : on tape
• CPC Class Codes: H04N 5/78263 : for recording on tracks inclined relative to the direction of movement of the tape
• CPC Class Codes: H04N 5/9206 : the additional signal being a character code signal
• CPC Class Codes: H04N 7/088 : the inserted signal being digital
• CPC Class Codes: H04N 7/0887 : for the transmission of programme or channel identifying signals
• CPC Class Codes: H04N 7/0888 : Subscription systems therefor
• CPC Class Codes: H04N 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

Apparatus and methods are provided for encrypting and decrypting information having a header portion and a body portion. The decrypting method includes the steps of reading a current month from a clock, extracting an odd/even month indication from the header portion, generating a first key based on the current month if the odd/even indication is odd and the current month is odd or if the odd/even indication is even and the current month is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month is even or if the odd/even indication is even and the current month is odd, and using the first key for decrypting the encrypted body portion to generate a decrypted body portion.

Claims

1. A method for encrypting information having a header portion and a body portion comprising the steps of:

reading a current month from a clock having an output as a function of time;

setting an odd/even month indication in the header portion to odd, if the current month read from the clock is an odd month, otherwise, setting an odd/even month indication in the header portion to even, if the current month read from the clock is an even month;

generating a first key based on the current month read from the clock if the odd/even indication is odd and the current month read from the clock is odd or if the odd/even indication is even and the current month read from the clock is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month read from the clock is even or if the odd/even indication is even and the current month read from the clock is odd;

using the first key for encrypting the body portion to generate an encrypted body portion; and

embedding the encrypted body portion and the header portion within a video signal to form a composite video signal.

2. The method of claim 1 further comprising the step of transmitting the composite video signal having the embedded encrypted body portion and the header portion.

3. The method of claim 1 further comprising the step of recording the composite video signal having the embedded encrypted body portion and the header portion.

4. The method of claim 1 further comprising the step of scrambling the encrypted body portion using a scrambling key.

5. The method of claim 4 wherein the step of scrambling the encrypted body portion using the scrambling key comprises the steps of:

assigning each bit of the scrambling key to a number of pairs of characters in the encrypted body portion;

swapping the characters of the pair, if the assigned bit is of a first type, otherwise, not swapping the characters of the pair, if the assigned bit is of a second type; and

repeating the steps of swapping or not swapping for all pairs of characters of the encrypted body portion.

6. The method of claim 1 wherein the step of embedding the encrypted body portion and the header portion within a video signal to form a composite video signal comprises the step of encoding the encrypted body portion and the header portion into vertical blanking interval lines of the video signal.

7. The method of claim 1 wherein the step of using the first key for encrypting the body portion to generate an encrypted body portion comprises the steps of:

selecting a first table using the first key;

mapping each part of the body portion to a first encrypted part using the first table; and

concatenating each first encrypted part to form an encrypted body portion.

8. The method of claim 7 wherein the step of mapping each part of the body portion to a first encrypted part using the first table comprises the steps of:

selecting a second table using the first key; and

mapping each first encrypted part to a second encrypted part using the second table.

9. The method of claim 1 wherein the step of generating a first key comprises the step of performing a table lookup.

10. A method for decrypting information in a composite video signal having an embedded header portion and an encrypted body portion, the method comprising the steps of:

reading a current month from a clock having an output as a function of time;

extracting an odd/even month indication from the header portion;

generating a first key based on the current month read from the clock if the odd/even indication is odd and the current month read from the clock is odd or if the odd/even indication is even and the current month read from the clock is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month read from the clock is even or if the odd/even indication is even and the current month read from the clock is odd; and

using the first key for decrypting the encrypted body portion to generate a decrypted body portion.

11. The method of claim 10 further comprising the step of recording the decrypted body portion and the header portion on a video cassette tape.

12. The method of claim 10 further comprising the step of descrambling the encrypted body portion using a scrambling key.

13. The method of claim 12 wherein the step of descrambling the encrypted body portion using the scrambling key comprises the steps of:

assigning each bit of the scrambling key to a number of pairs of characters in the encrypted body portion;

swapping the characters of the pair, if the assigned bit is of a first type, otherwise, not swapping the characters of the pair, if the assigned bit is of a second type; and

repeating the steps of swapping or not swapping for all pairs of characters of the encrypted body portion.

14. The method of claim 10 further comprising the step of decoding a vertical blanking interval to decode the embedded headed portion and the encrypted body portion from the composite video signal.

15. The method of claim 10 wherein the step of using the first key for decrypting the encrypted body portion to generate a decrypted body portion comprises the steps of:

using the first key to select a first table;

mapping each part of the encrypted body portion to a first decrypted part using the first table; and

concatenating each first decrypted part to form a decrypted body portion.

16. The method of claim 15 wherein the step of mapping each part of the encrypted body portion to a first decrypted part using the first table comprises the steps of:

selecting a second table using the first key; and

mapping each first decrypted part to a second decrypted part using the second table.

17. The method of claim 10 wherein the step of generating a first key comprises the step of performing a table lookup.

18. The method of claim 10 further comprising the step of receiving the composite video signal from a transmitted signal.

19. The method of claim 10 further comprising the step of receiving the composite video signal from a recorded signal.

20. An apparatus for encrypting information having a header portion and a body portion, the apparatus comprising:

a clock having an output as a function of time;

means for reading a current month from the clock;

means for setting an odd/even month indication in the header portion to odd, if the current month read from the clock is an odd month, otherwise, setting an odd/even month indication in the header portion to even, if the current month read from the clock is an even month;

means for generating a first key based on the current month read from the clock if the odd/even indication is odd and the current month read from the clock is odd or if the odd/even indication is even and the current month read from the clock is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month read from the clock is even or if the odd/even indication is even and the current month read from the clock is odd;

means for encrypting the body portion using the first key to generate an encrypted body portion; and

means for embedding the encrypted body portion and the header portion within a video signal to form a composite video signal.

21. The apparatus of claim 20 further comprising means for transmitting the composite video signal.

22. The apparatus of claim 20 further comprising means for recording the composite video signal.

23. The apparatus of claim 20 further comprising means for scrambling the encrypted body portion using a scrambling key.

24. The apparatus of claim 20 wherein the means for embedding the encrypted body portion and the header portion within a video signal to form a composite video signal comprises means for embedding the encrypted body portion and the header portion into vertical blanking interval lines of the video signal.

25. The apparatus of claim 20 wherein the means for encrypting the body portion using the first key to generate an encrypted body portion comprises:

means for selecting a first table using the first key;

means for mapping each part of the body portion to a first encrypted part using the first table; and

means for concatenating each first encrypted part to form an encrypted body portion.

26. The apparatus of claim 20 wherein the means for mapping each part of the body portion to a first encrypted part using the first table comprises:

means for using the first key to select a second table; and

means for mapping each first encrypted part to a second encrypted part using the second table.

27. The apparatus of claim 20 wherein the means for generating a first key comprises mean for performing a table lookup.

28. An apparatus for decrypting information having a header portion and an encrypted body portion embedded in a composite video signal, the apparatus comprising:

a clock having an output as a function of time;

means for reading a current month from the clock;

means for extracting an odd/even month indication from the header portion;

means for generating a first key based on the current month read from the clock if the odd/even indication is odd and the current month read from the clock is odd or if the odd/even indication is even and the current month read from the clock is even, otherwise generating the first key based on a month previous to the current month read from the clock if the odd/even indication is odd and the current month read from the clock is even or if the odd/even indication is even and the current month read from the clock is odd; and

means for using the first key for decrypting the encrypted body portion to generate a decrypted body portion.

29. The apparatus of claim 28 further comprising:

means for combining the decrypted body portion and the header portion to form a data packet; and

means for recording the data packet on a video cassette tape.

30. The apparatus of claim 28 further comprising means for descrambling the encrypted body portion using a scrambling key.

31. The apparatus of claim 30 wherein the means for descrambling the encrypted body portion using the scrambling key comprises:

means for assigning each bit of the scrambling key to a number of pairs of characters in the encrypted body portion; and

means for swapping the characters of each pair, if the assigned bit assigned to the pair is of a first type, otherwise, not swapping the characters of the pair, if the assigned bit is of a second type.

32. The apparatus of claim 28 further comprising means for decoding a vertical blanking interval to extract the embedded headed portion and the encrypted body portion from the composite video signal.

33. The apparatus of claim 28 wherein the means for using the first key for decrypting the encrypted body portion to generate a decrypted body portion comprises:

means for selecting a first table using the first key;

means for mapping each part of the encrypted body portion to a first decrypted part using the first table; and

means for concatenating each first decrypted part to form an decrypted body portion.

34. The apparatus of claim 33 wherein means for mapping each part of the encrypted body portion to a first decrypted part using the first table comprises:

means for using the first key to select a second table; and

means for mapping each first decrypted part to a second decrypted part using the second table.

35. The apparatus of claim 28 wherein the means for generating a first key comprises means for performing a table lookup.

36. The apparatus of claim 28 further comprising means for receiving the composite video signal from a transmitted signal.

37. The apparatus of claim 28 further comprising means for receiving the composite video signal from a recorded signal.

38. A method for encrypting and sending information having a header portion and a body portion and for decrypting the received information comprising the steps of:

reading a first current month from a first clock having an output as a function of time;

setting an odd/even month indication in the header portion to odd, if the first current month read from the first clock is an odd month, otherwise, setting an odd/even month indication in the header portion to even, if the first current month read from the first clock is an even month;

generating a first key based on the first current month read from the first clock if the odd/even indication is odd and the first current month read from the first clock is odd or if the odd/even indication is even and the first current month read from the first clock is even, otherwise generating the first key based on a month previous to the first current month read from the first clock if the odd/even indication is odd and the first current month read from the first clock is even or if the odd/even indication is even and the first current month read from the first clock is odd;

using the first key for encrypting the body portion to generate an encrypted body portion;

embedding the encrypted body portion and the header portion within a video signal to form a composite video signal;

transmitting the composite video signal;

receiving the transmitted composite video signal;

reading a second current month from a second clock having an output as a function of time;

extracting an odd/even month indication from the received header portion;

generating a second key based on the second current month read from the second clock if the odd/even indication is odd and the second current month read from the second clock is odd or if the odd/even indication is even and the second current month read from the second clock is even, otherwise generating the second key based on a month previous to the second current month read from the second clock if the odd/even indication is odd and the second current month read from the second clock is even or if the odd/even indication is even and the second current month read from the second clock is odd; and

using the second key for decrypting the received encrypted body portion to generate a decrypted body portion.

39. The method of claim 38 further comprising the steps of:

scrambling the encrypted body portion using a first scrambling key; and

descrambling the received encrypted body portion using a second scrambling key.

40. The method of claim 39 wherein:

the step of scrambling the encrypted body portion using the first scrambling key comprises the steps of;

assigning each bit of the first scrambling key to a number of pairs of characters in the encrypted body portion;

swapping the characters of the pair, if the assigned bit is of a first type, otherwise, not swapping the characters of the pair, if the assigned bit is of a second type; and

repeating the steps of swapping or not swapping for all pairs of characters of the encrypted body portion.

41. The method of claim 38 wherein the step of embedding the encrypted body portion and the header portion within a video signal to form a composite video signal comprises the step of encoding the encrypted body portion and the header portion into vertical blanking interval lines of the video signal.

42. The method of claim 39 wherein the step of descrambling the encrypted body portion using the second scrambling key comprises the steps of:

assigning each bit of the second scrambling key to a number of pairs of characters in the encrypted body portion;

swapping the characters of the pair, if the assigned bit is of a first type, otherwise, not swapping the characters of the pair, if the assigned bit is of a second type; and

repeating the steps of swapping or not swapping for all pairs of characters of the encrypted body portion.

43. The method of claim 38 further comprising the step of decoding a vertical blanking interval to decode the embedded headed portion and the encrypted body portion from the composite video signal.