Masc Encryption

[RayAir]

I bought a pair of MASC encrypted HT600e's off of Ebay U.K andwas wondering if anyone knows how the scrambling works? It sounds like variable band inversion, but possibly with multiple bands? Maybe someone from the U.K would be more familiar with MASC as little info. is available about it on the internet.

 

[morfis]

Marconi Advanced Scrambler (MASC) encryption was developed by Marconi from work done at Bristol University. It uses variable band inversion (some people would call it "rolling code inversion"). The transmitted audio is inverted around a constantly varying inversion point. A 'key code' determines the pseudo-random inversion point. IIRC there were around a billion key codes.

At the beginning and end of each transmission a data burst is sent, along with small data bursts several times a second throughout the transmission. This enables the transmitting and receiving radios to remain synchronised. There is other data sent such as the identity of the radio.

A good source of more detailed info might be one of the UK radio user groups as many people have bought the surplus radios and now use them illegally in the PMR446 band.

 

[citylink_uk]

Try joining the HT600E Yahoo group, im certain they will be able to help.

http://groups.yahoo.com/group/HT600E/

Rich

 

[RayAir]

Masc

This is about the best article on the old MASC scrambling that I could find. Turns out it uses band reordering, not rolling code.
http://borg.shef.ac.uk/~ianw/masc/

 

[fez_uk]

nice buy mate, do you mind me asking how much they cost?

 

[RayAir]

I paid about $350 USD. A decent price since they are so hard to find and I have an interest in them. I would like to find a pair of the HT6000's with MASC.