Logbook of The World

Logbook of the World (LoTW) is a web-accessed database provided by the American Radio Relay League (ARRL) to implement a contact verification service among amateur radio operators. Using LoTW, radio amateurs (hams) are able to claim and verify contacts (QSOs) made with other amateurs, generally for claiming credit for operating awards, such as DXCC. Previously, hams had to rely on paper QSL cards and submit to ARRL; a slow and somewhat expensive process. LoTW began operation in 2003.

Confirmation process

The LoTW system uses "secure" authentication using cryptographic key distribution. An amateur's computer-based logbook, in ADIF or Cabrillo format, have to be "signed" using a key obtained from ARRL. (Logbook data includes callsigns and locations of stations, contact time, frequency, and operating mode.) ARRL assigns such keys to amateurs who appear in the U.S. FCC licensing database or to non-US amateurs who provide alternate proof of identity.

Once a log file is signed using ARRL's "TrustedQSL" (or equivalent) program, it is uploaded to the ARRL server and entered in the database.

Log records in the LoTW database are automatically compared so that when a contact at a particular time, operating mode, and frequency band is claimed by both participating amateurs (both of whom must have submitted their logs), a "QSL" (confirmation) is declared for a later award claim, e.g., for contacts with all U.S. states or 100 different countries. The matching process is blind, meaning that neither of the two stations can see pending confirmations before they uploaded a matching record. The LoTW QSL is purely electronic; there are no paper confirmations. However, a participant is able to print out a record of each confirmed contact, complete with its LOTW record number.