Patent EP0674440B1 successfully refreshed from Google Patents.
EP0674440B1
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EP
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A process for encryption and decryption of a bit stream containing digital information
Assignee: Nokia Technology GmbH
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Filing: 1995-03-16
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Granted: 1999-05-19
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Expires: 2015-03-16
Abstract
No abstract record available.
Inventors
- 👤 Mauri Kangas
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 12:55
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/60; H04N19/61; H04N21/00; H04N21/20; H04N21/23; H04N21/236; H04N21/23605; H04N21/238; H04N21/2389; H04N21/23895; H04N21/40; H04N21/43; H04N21/438; H04N21/4385; H04N21/43853; H04N7/00; H04N7/16; H04N7/167; H04N7/1675; H04N19/70
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
213 words
A process for encryption of a bit stream containing digital video or digital audio or data
information, whereby the bit stream is formed by arranging each information into first
(PES) packets comprising a first (PES) header and a first information section formed by
information bytes, whereby for transmission each (PES) packet is divided into second
transport stream (TS) packets of a fixed length, comprising a second (TS) header and a
second information section formed by a fixed first number of information bytes, whereby
a second smaller number of bytes form an encryption block and each second information
section contains several encryption blocks, characterized in that in the encryption of the (PES) packets a first encryption key is used in a bit or byte based
encryption algorithm, whereby the encryption is made with an accuracy of one bit or one
byte at a time, and in the encryption of transport stream (TS) packets a second encryption key is used in a
byte based encryption algorithm, whereby the encryption of the section to be encrypted is
made by blocks and that information about how the (PES) packets and the transport stream (TS) packets are
encrypted is included in the transport stream (TS) packet header, and that the transport stream (TS) packet header is not encrypted.
Claim 2
Dependent Claim
37 words
The process of claim 1, characterized in that the block encryption of the transport
stream (TS)packets is performed only on that section of the packet to be encrypted which
has a length of the encryption block multiple.
Claim 3
Dependent Claim
83 words
The process of claim 1, characterized in that the block based encryption algorithm is
used over the whole section to be encrypted, so that first a number of bytes corresponding
to a multiple of the encryption block is encrypted, and that during a second encryption
phase a multiple of the encryption block is formed by performing the encryption also both
on bytes of a section shorter than the block length and on a desired number of bytes of the
section already once encrypted.
Claim 4
Dependent Claim
44 words
The process of claim 1, 2 or 3, characterized in that the (PES) packet encryption
algorithm does not limit the length of the section to be encrypted, but that it can be of any
length with an accuracy of a byte or a bit.
Claim 5
Dependent Claim
21 words
The process of claim 4, characterized in that the (PES) packet encryption algorithm
is a PRBS algorithm (Pseudo Random Bit Sequence).
Claim 6
Dependent Claim
17 words
The process of claims 1 to 5, characterized in that the (PES) packet header is not
encrypted.
Claim 7
Dependent Claim
19 words
The process of claims 1 to 6, characterized in that the first and second encryption keys
are the same.
Claim 8
Dependent Claim
204 words
A process for decryption of a bit stream containing digital video or digital audio or data
information, whereby the bit stream is formed by arranging each information into first
(PES) packets comprising a first (PES) header and a first information section formed by
information bytes, whereby for transmission each (PES) packet is divided into second
transport stream (TS) packets of a fixed length, comprising a second (TS) header and a
second information section formed by a fixed first number of information bytes, whereby
a second smaller number of bytes form a decryption block and each second information
section contains several decryption blocks, characterized in that information about how the (PES) packets and the transport stream (TS) packets are
encrypted is read from the transport stream (TS) packet header, which is not encrypted. in the decryption of transport stream (TS) packets a first decryption key is used in a byte
based encryption algorithm, whereby the decryption of the section to be decrypted is made
by blocks and in the decryption of the (PES) packets a second decryption key is used in a bit or byte
based decryption algorithm, whereby the decryption is made with an accuracy of one bit
or one byte at a time.
Claim 9
Dependent Claim
91 words
The process of claim 8, characterized in that when it is identified from the transport
stream (TS) header that the block based encryption algorithm is used over the whole
section to be decrypted, first a number of bytes corresponding to a multiple of the
decryption block is decrypted, and during a second decryption phase a multiple of the
decryption block is formed by performing the decryption also both on bytes of a section
shorter than the block length and on a desired number of bytes of the section already once
decrypted.
Claim 10
Independent Claim
209 words
A device for encryption of a bit stream containing digital video or digital audio or data
information, comprising means for forming the bit stream by arranging each information
into first (PES) packets comprising a first (PES) header and a first information section
formed by information bytes, means for slicing each (PES) packet for transmission into
second transport stream (TS) packets of a fixed length, comprising a second (TS) header
and a second information section formed by a fixed first number of information bytes,
whereby a second smaller number of bytes form an encryption block and each second
information section contains several encryption blocks, characterized in that it further
comprises means for the encryption of the (PES) packets using a first encryption key in a bit or byte
based encryption algorithm, whereby the encryption is made with an accuracy of one bit
or one byte at a time, and means for the encryption of transport stream (TS) packets using a second encryption
key in a byte based encryption algorithm, whereby the encryption of the section to be
encrypted is made by blocks and means for providing information about how the (PES) packets and the transport stream
(TS) packets are encrypted to be included in the transport stream (TS) packet header.
Claim 11
Independent Claim
205 words
A device for decryption of a bit stream containing digital video or digital audio or data
information, whereby the bit stream is formed by arranging each information into first
(PES) packets comprising a first (PES) header and a first information section formed by
information bytes, whereby for transmission each (PES) packet is divided into second
transport stream (TS) packets of a fixed length, comprising a second (TS) header and a
second information section formed by a fixed first number of information bytes, whereby
a second smaller number of bytes form a decryption block and each second information
section contains several decryption blocks, characterized in that it comprises means for reading from the transport stream (TS) packet header information about how
the (PES) packets and the transport stream (TS) packets are encrypted, means for the decryption of transport stream (TS) packets by using a first decryption key
in a byte based encryption algorithm, whereby the decryption of the section to be
decrypted is made by blocks and means for the decryption of the (PES) packets by using a second decryption key in a bit
or byte based decryption algorithm, whereby the decryption is made with an accuracy of
one bit or one byte at a time.
Claim 12
Dependent Claim
77 words
The device of claim 11, characterized in that it comprises first means for decryption
of a first number of bytes corresponding to a multiple of a decryption block, that it
comprises second means for decryption a second decryption phase, wherein a multiple of
the decryption block is formed by performing the decryption also both on bytes of a
section shorter than the block length and on a desired number of bytes of the section
already once decrypted.
References Cited (Backward Citations)
No citation records indexed.
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