SECMPEG

NAME

SYNOPSIS

DESCRIPTION

Secmpeg accepts the following options listed below:

-s

Switching on silence mode. No output, except errors, will be generated. Normally, secmpeg will at least echo the used time for the coding or decoding process or, during a integrity-check, echo the result of it. This option has to be given before every other.

-e

Switching to encoding mode. Encoding means to insert confidentiality and integrity data into the video-stream and copying the resulting stream to another given file. A confidentiality level (clevel) ,a security-key (key) ,a integrity-level (ilevel) ,a MPEG-I inputfile infile.mpg and a outputfile (outfile.mpg) have to be given on the command line. The resulting stream will NOT we playable as an MPEG-I-video, because additional data is inserted (even if no encryption is done).

The following methos are available for the confidentiality-level:

0

Only the MPEG-stream-headers and the first slice-header of every frame are encrypted. This method is very quick, but not safe.

1

The MPEG-stream-headers and ALL slice-headers are encrypted. This method is still very quick, but still not safe.

2

Everything like method 1 and the first macroblock after each slice-header is encrypted. This method is still quick and looks very safe (all offsets are encrypted, the locating of relevant data looks rather difficult).

3

Everything like method 2 and the I-frames are encrypted completely. The method is not so quick anymore, but definitely safe (only intracoded macroblocks are copied from the original stream, but to find there location looks very difficult). This method is much quicker than encrypting the complete stream.

4

Everything like method 3 and all intracoded macroblocks are encrypted as well. The method could be slower than a complete encryption of the whole stream, but is the safest one.

The following methos are available for the integrity-level:

0

A 16-bit CRC is performed on all header data.

1

A 16-bit CRC is performed on all header data and all frames.

2

A 32-bit CRC is performed on all header data.

3

A 32-bit CRC is performed on all header data and all frames.

CRC-checks are very quick. The suggested mode for integrity is method 3.

If a negativ value for the confidentiality-level or integrity-level is given (f.e. -1), no encryption or CRC-checks are encoded.

-d

Switching to decoding mode. Decoding means to extract the original MPEG-I-stream from a encoded secmpeg -stream. If a integrity-method was encoded, a integrity-check is performed while decoding. If the stream was crypted, the key and the source filename and the target filename have to be given. Otherwise only the two filenames have to be given.

-c

A integrity-check is performed on a with secmpeg encoded MPEG-I-stream. No output file is generated, no service information is deleted during this option. If the option -s (silence) is enabled, only errors will be generated, otherwise a message of success will be shown. If the stream was crypted, a additional key has to be given.

-E

The complete source file will be crypted with a given key to produce a target file of the same length. The method is save and slow.

-D

The completely encrypted file will be decrypted with the given key.

-C

The CRC-value will be generated over the complete source file and printed to stdout. If the option -s (silence) is enabled, only errors will be generated.

Surely, the last three methods can be used on every kind of stream.

If a dash (-) is given instead of filenames (source and/or target) secmpeg takes input from stdin and writes output to stdout.

-v

Prints the version-number and -date of the program.

EXAMPLES

secmpeg -e 2 password -1 in.mpg out.mpg

To encode the same file with a full 32-bit CRC, but without encryption, enter:

secmpeg -e -1 3 in.mpg out.mpg

To do both enter:

secmpeg -e 2 password 3 in.mpg out.mpg

To check the integrity of the last process in silence mode enter:

secmpeg -s -c password out.mpg

To decode the last file to orig.mpg enter:

secmpeg -d password out.mpg orig.mpg

Other possible commands are:

secmpeg -e -2 password 3 - - < in.mpg more
secmpeg -E password in.mpg out.mpg
secmpeg -D password out.mpg orig.mpg
cat in.mpg | secmpeg -C -

BUGS

AUTHORS

Juergen Meyer
Sonnenallee 50
12045 Berlin GERMANY Access: jm@cs.tu-berlin.de

Frank Gadegast
Leibnizstr. 30
10625 Berlin GERMANY Access: phade@cs.tu-berlin.de

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the archive remains complete, that this author notice will appear in all copies and as long as you don't try to make money off it, or pretend that you wrote it.

Index

NAME

SYNOPSIS

DESCRIPTION

EXAMPLES

BUGS

AUTHORS