|
|
|
|
← UK Data BID/610 →
Synchronizer
- not in collection
BID/700, also known by its codename VENDOR, was a synchronizing unit,
or synchronizer, for the BID/610 (ALVIS) cipher machine.
It was developed by Plessey Crypto in Liverpool (UK)
and allowed ALVIS to be used in mode B (synchronous operation).
It also added Traffic Flow Security, or TFS.
|
Due to the way the Non-Linear Feedback Shift Registers (NLFSRs) inside the
crypto logic of the BID/610 work, any transmission errors would propagate
through the system, resulting in a garbled output. It then took a certain
number of characters before it was synchronized again.
When the synchronizer was added, it produced a continuous timing,
in order to keep the receiver in sync with the distant transmitter,
even if the signal was distored or completely
lost for some time.
The synchronizer was typically used on low-quality HF radio links
and bad phone lines.
The image on the right shows a complete BID-610 system with occupies a
full-height 19" rack. The Large unit at the top is the BID/700 unit [2].
It is covered by a metal front panel for TEMPEST reasons,
and has an oval window through which its indicator lamps are visible.
The system shown here was used on a full-duplex HF radio link.
➤ More about BID/610 (ALVIS)
|
|
|
The image on the right shows part of an
array of BID/610 systems
that were in use at the Foreign Office in Canada, probably during the
1960s or 70s [4]. Only the first two racks have a BID/700 mounted at the
top. It is believed that only these two units were used in MODE B
(synchronised).
The cover of the fist BID/700 has been removed, giving us
a glimpse of the complex electronics inside.
|
|
|
- All-space-deleter added for T.A.R.E. operation
- Improved crypto security
- Conversion to standard low-level logic 6V-0V-6V
- Elimination of security hazard (not low-level version)
- Switch added for 7 or 7½ unit operation
- Prevention of garbled receive copy
|
- Technical notes on BID/610, BID/700 and BAM/650, Part 1
Part of technical training course in 1975.
Secret/Confidential notebook 1 . CM-301917-C [3].
- Technical notes on BID/610, BID/700 and BAM/650, Part 2
Part of technical training course in 1975.
Secret/Confidential notebook 1 . CM-301918-C [3].
- BID/701/12A, Technical Description
Not in collection.
- BID/701/12B, Fault Finding and Repair Data
Not in collection.
- BID/701/13, Unit and Field Repair
Not in collection.
- BID/701/14, Base repairs
Not in collection.
- BID/701/37(1), Modifications
Not in collection.
- BID/701/20(2), Illustrated spare parts list
Not in collection.
|
-
Declared unclassified by the author in 1993.
|
|
|
Any links shown in red are currently unavailable.
If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Monday 30 May 2016. Last changed: Wednesday, 16 January 2019 - 22:56 CET.
|
 |
|
|
|