|
US2518458A
|
|
Authenticating device
|
|
US2877565A
|
|
Electrical cryptograph
|
|
US2465367A
|
|
System for enciphering facsimiles
|
|
US2552548A
|
|
Facsimile enciphering system
|
|
US2395863A
|
|
Cryptographic device
|
|
US2139676A
|
|
Cryptographic apparatus
|
|
US2140424A
|
|
Cryptographic device
|
|
US2224646A
|
|
Electric control system for tabulating cards, documents, and the like
|
|
US2166137A
|
|
Electrical switching mechanism
|
|
US2080416A
|
|
Message authenticating system
|
|
US2028772A
|
|
Cryptographic system
|
|
US1608590A
|
|
Alphabetical chart
|
|
US1530660A
|
|
Printing-telegraph system
|
|
US1694874A
|
|
Method of electrical signaling
|
|
US1516180A
|
|
Secret signaling system employing apparatus for automatically enciphering and deciphering messages
|
|
US1522775A
|
|
Secret-signaling apparatus for automatically enciphering and deciphering messages
|
