| 摘要 |
1,190,809. Random number generators. TELEFONAKTIEBOLAGET L. M. ERICSSON. 26 June, 1967, No. 29475/67. Heading G4D. A random number generator comprises a set of recirculating shift registers the outputs of which feed into different parts of a chain of AND gates and exclusive-OR gates. Straight shift registers X1-X8 are fed by a common pulsed input A and are of different lengths as shown. The last stages feed AND gates 02-08. Shift registers Y1-Y7 have selected stages connected to exclusive-OR gates such as IE11 used to set the first stage and also to feed exclusive- OR gates such as IE1 in the chain. Shift registers Z1, Z2 recirculate via one or a combination of three exclusive-OR gates. Selected stages in the shift registers may be preset (Fig. 3, not shown) before an operation begins. The resultant stream of pulses at F may be used to cipher and decipher digitalized information.
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