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CD ROM Paradise Collection 4 1995 Nov.iso
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INSTALL.DAT
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TECHINFO.DOC
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1995-03-14
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File Maven (tm) 3.0
Technical/Misc Information
System Requirements
-------------------
File Maven will run on any 8088/286/386/486/Pentium compatible PC that has
640K of conventional RAM (460K free) and DOS 3.0 or higher.
Serial Link Null Modem Cable
----------------------------
There are basically two types of null modem cables: 3-wire and 7-wire. The
3-wire cable contains only transmit, receive, and ground lines. The
7-wire cable has four additional handshaking lines. File Maven supports
both cables but users should get a 7-wire cable if possible for faster file
transfers. A 7-wire cable can be used in 3-wire link mode, but the reverse
is not true. Null modem cables are available in most computer supply stores.
If possible, look for a 4-headed null-modem cable that can support both 9-pin
and 25-pin serial ports at either end.
DB25 DB9 DB9 DB25
---- --- --- ----
2 3 TX -- RX 2 3
3 2 RX -- TX 3 2
4 7 RTS -- CTS 8 5 <-- 7-wire only
5 8 CTS -- RTS 7 4 <-- 7-wire only
6 6 DSR -- DTR 4 20 <-- 7-wire only
7 5 SG -- SG 5 7
20 4 DTR -- DSR 6 6 <-- 7-wire only
3-wire/7-Wire Null Modem Pin Configuration
Parallel Link Cable
-------------------
The parallel link mode is only available in the fully-licensed, registered
version of File Maven. A parallel link cable is included when you purchase
the registered version. There are basically two types of parallel link
cables: 4-bit and 8-bit. The 8-bit cable contains more lines and uses
an additional register on the parallel port for faster data transfer.
File Maven supports both cables. An 8-bit cable can be used in 4-bit mode
but the reverse is not true. The parallel link has three advantages over
the serial link:
1. The 8-bit parallel link is up to 3 times faster than the 7-wire serial
link at the fastest baud rate.
2. All standard parallel ports are 25-pin, so 4-headed cables are never
needed.
3. There are no baud rate settings with the parallel link.
DB25M DB25M
----- -----
1 ───────────── 1 <-- 8-bit only
2 ───────────── 15
3 ───────────── 13
4 ───────────── 12
5 ───────────── 10
6 ───────────── 11
10 ───────────── 5
11 ───────────── 6
12 ───────────── 4
13 ───────────── 3
14 ───────────── 14 <-- 8-bit only
15 ───────────── 2
16 ───────────── 16 <-- 8-bit only
17 ───────────── 17 <-- 8-bit only
25 ───────────── 25
4-bit/8-bit Parallel Pin Configuration
Ports and Interrupts
--------------------
File Maven reads the serial and parallel ports addresses from a 14-byte
array in your computer's BIOS data segment starting at 0040:0000. The four
possible COM port addresses are contained in the first 8 bytes and the three
possible LPT port addresses are contained in the next 6 bytes. File Maven
uses direct polling instead of interrupt driven communications for the
fastest possible connections. Therefore, there no are IRQ settings to
adjust.
Blowfish File Encryption
------------------------
File Maven uses Blowfish for file encryption. Blowfish, a variable size
key block-encryption algorithm, was developed by Bruce Schneier, author of
"Applied Cryptography" (Wiley), and presented in the April 1994 edition of
Dr. Dobb's Journal. I thank Mr. Schneier for placing the algorithm in the
public domain, unpatented, so that it can be freely used by anyone.
File Maven's implementation differs from the original specification in two
areas. First, instead of initializing the s-boxes with the hexadecimal
digits of pi, File Maven uses the output of a pseudo-random number generator.
This eliminates the need for a separate 4k data file. The PRNG equation
used is: rng(i)=rng(i-1)*134775813+1 where rng is a 32-bit variable
initialized to ffffffff hex. Second, PCs with Intel CPUs store data in
little endian format (least significant byte first in a multi-byte word).
The original specification converts each block to big endian format before
encrypting and back to little endian format before saving. Since this only
slows encryption and does not change the security of the algorithm, File
Maven skips the conversions.
File Maven uses the Secure Hash Algorithm (SHA) to generate the session
key. The SHA was developed by The National Institute of Standards and
Technology (NIST), along with the National Security Agency (NSA). The
SHA is considered by many cryptography experts to be one of the most secure
one-way hash algorithms available. File Maven takes the user's pass
phrase, converts it to uppercase, and runs it through the SHA. This
results in a 160-bit message digest, or hash value. When using the
Casual option, File Maven only uses the 32 most significant bits for the
session key. When using the Secure option, all 160 bits are used.
Because of the efficient design of the Blowfish algorithm, there is no
speed penalty when using the Secure option.
Unfortunately, because the U.S. government classifies strong encryption
software as "munitions" and restricts its export, the Secure option is only
available in the Registered version sent to citizens of the U.S. and Canada.
Registered users in other countries receive the International Registered
version that only has the Casual option. The 32-bit key still provides over
4 billion combinations that should keep your friends out of your private
files, assuming you did not use a password or pass phrase that could be
easily guessed. On the other hand, the 160-bit key has over 10^48 (10
raised to the 48th power) combinations. Assuming a brute force attack is
the best way to break it, a trillion supercomputers, each trying a trillion
keys per second, would take about 463 trillion centuries to try all
combinations. In either case, don't call me if you forget a password. I
have no method of recovering encrypted files without the password. File
Maven leaves the original plaintext file in place so if you want it
permanently erased, use the Wipe command, not the Delete command.
Programming Language
--------------------
File Maven 3.0 was written using the Borland Pascal 7.01 compiler. Version
3.0 represents a complete rewrite since version 2.2 and took over 7 months
to complete, outside of my regular full-time job. File Maven now contains
over 15,000 lines of code. The low level Link functions were written with
in-line assembly code. All code is the original work of the author except
for the compiler's run-time library. No external libraries were used.
Special thanks goes to my chief beta tester, Gerald Stump, and to my other
testers: Paul Bookout, Ed Simpson, Joe Branch, Ron Briggs, and Joe Stump.
Contacting the Author
---------------------
For technical support or other inquiries, send a note to:
Kent Briggs
109A Romana Circle
Hewitt, TX 76643
or e-mail:
kbriggs@execpc.com (Internet)
72124,3234 (CompuServe)
Internet users can "finger kbriggs@execpc.com" or visit my World Wide Web
(WWW) site at http://execpc.com/~kbriggs to get the latest info on my
shareware and freeware products. Also check the IBMSYS forum on CompuServe,
SimTel's mirror site at oak.oakland.edu, and Exec-PC BBS for the latest
versions. Do you have suggestions for improvement? Would you like to see a
Windows/Windows 95 version? Drop me a note and let me know.