Given the impossibility of solving without more info, my best guess is the author used to obscure a phrase like "open the file..." or something similar, and "Download-" is plaintext indicating the action.
Given the repeated "tt" and "rm" patterns, one common guess is Atbash (A↔Z, B↔Y, etc.) or a Caesar shift.
Given it’s from a paper (or puzzle), the intended solution might be for the whole string except "Download-" . Download- nwdz lshrmwtt khlyjyt fatht layf ttshrmt...
Right shift: n→m, w→e, d→f, z→/ → mef/ — maybe part of a path.
Next: lshrmwtt l(12)→o(15) s(19)→h(8) h(8)→s(19) r(18)→i(9) m(13)→n(14) w(23)→d(4) t(20)→g(7) t(20)→g(7) → ohsingdg — still nonsense. Given the impossibility of solving without more info,
This looks like a fragment of a coded or encrypted message, possibly using a simple substitution cipher (like Atbash, Caesar, or a keyboard shift).
Let’s try Atbash on lshrmwtt : l→o, s→h, h→s, r→i, m→n, w→d, t→g, t→g → ohsingdg — doesn’t look right. Right shift: n→m, w→e, d→f, z→/ → mef/
nwdz ROT13: a→n, b→o, but wait, do it properly: n→a, w→j, d→q, z→m → ajqm (no). Actually ROT13: n→a, w→j, d→q, z→m — yes, ajqm . Doesn’t look like English filename.
