Electronic File Wrappers | Electronic Patent Documents | Paper Patent Documents | Current as of: June, 1999
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DF | CLASS NOTES | |
1 | DF | CRYPTANALYSIS |
2 | DF | EQUIPMENT TEST OR MALFUNCTION INDICATION |
3 | DF | STORED INFORMATION ACCESS OR COPY PREVENTION |
4 | DF | .~ Digital data (e.g., software program protection, data encryption) |
5 | DF | .~ Video |
6 | DF | ELECTRIC SIGNAL MASKING |
7 | DF | .~ Video |
8 | DF | .~ By signal having discrete step amplitude variation |
9 | DF | ELECTRIC SIGNAL MODIFICATION (E.G., SCRAMBLING) |
10 | DF | .~ Video |
11 | DF | .~.~ Variable time delay modulation of baseband video signal |
12 | DF | .~.~ Carrier phase shift |
13 | DF | .~.~ Carrier frequency conversion |
14 | DF | .~.~ Nonstandard scan of video information |
15 | DF | .~.~ By modifying synchronizing signal |
16 | DF | .~.~ Record or coin controlled |
17 | DF | .~.~ Phase inversion of scan line information |
18 | DF | .~.~ Facsimile |
19 | DF | .~.~ Encrypting of accompanying audio signal |
20 | DF | .~.~ Control coding |
21 | DF | .~ Having transmission or distribution of key signal |
22 | DF | .~ With magnetic record carrier (e.g., tape, drum) |
23 | DF | .~ With user or record actuated authentication |
24 | DF | .~.~ Electronic funds transfer (e.g., automatic teller) |
25 | DF | .~.~ Computer |
26 | DF | .~ With mechanical control of signal encryption (e.g., cam) |
27 | DF | .~.~ By perforated record |
28 | DF | .~ By particular algorithmic function encoding |
29 | DF | .~.~ NBS/DES algorithm |
30 | DF | .~.~ Public key |
31 | DF | .~ Plural modulation of single carrier |
32 | DF | .~.~ Wobbling of carrier |
33 | DF | .~ Using plural paths or channels |
34 | DF | .~.~ Plural carrier frequencies |
35 | DF | .~ Variable time delay modulation |
36 | DF | .~ Time segment interchange |
37 | DF | .~.~ Block/data stream enciphering |
38 | DF | .~ Frequency shift or inversion |
39 | DF | .~.~ With plural band pass filters |
40 | DF | .~ With plural band pass filters |
41 | DF | .~ With quantizing and subsequent normalizing of signal (e.g., reentry telephone circuitry) |
42 | DF | .~ Data stream/substitution enciphering |
43 | DF | .~.~ Key sequence signal combined with data signal |
44 | DF | .~.~ With particular key generator |
45 | DF | .~.~.~ Multiple key level |
46 | DF | .~.~.~ Nonlinear (e.g., pseudorandom) |
47 | DF | .~.~.~ Plural generators |
48 | DF | .~ With particular synchronization or initiation |
49 | DF | .~ With digital signal handling (e.g., digital control, digital computer communication) |
50 | DF | .~.~ Including shift register or memory |
51 | DF | .~ With production of printed copy (e.g., printer, typewriter) |
52 | DF | .~ Including particular structure or housing (e.g., display, keyboard) |
53 | DF | .~.~ Audio transducer mounting or structure |
54 | DF | BY MODIFYING OPTICAL IMAGE (E.G., TRANSMISSIVE OVERLAY) |
55 | DF | WITH PRODUCTION OF PRINTED COPY (E.G., CRYPTOGRAPHIC PRINTER OR TYPEWRITER) |
56 | DF | SELECTIVELY MOVABLE ELEMENT HAVING CODE CHARACTERS |
57 | DF | .~ Rotatable |
58 | DF | .~.~ Characters on peripheral surface (e.g., cylinder section) |
59 | DF | MISCELLANEOUS |