This is a copy of the PGP "biometric" word list, which actually comprises two lists, each with 256 entries each. (One contains only two-syllable words, and the other contains only three-syllable words.) The words were selected in 1995 to be as phonetically distinct from one another as feasible.
The Wikipedia entry describes the lists as being licensed under the GNU Free Documentation License, although I have no awareness of any publicly available primary sources stating this. The underlying source code for PGPfone, which was the motivation for the list, is licensed MIT.
The lists have been extracted from this archived documentation.