Some algebraic aspects of field quantization in space-time with bounda
ries are discussed. We introduce an associative algebra B-R, whose exc
hange properties are inferred from the scattering processes in integra
ble models with reflecting boundary conditions on the half line. The b
asic properties of B-R are established and the Fock representations as
sociated with certain involutions in B-R are derived. We apply these r
esults for the construction of quantum fields and for the study of sca
ttering on the half line.