Israel was redeemed from Egypt for four reasons – that they did not change their names, their language, they did not gossip, and there could not be found among them anyone promiscuous.
(Vayikra Rabbah 32:5; Bamidbar Rabbah 20:22; Shir HaShirim Rabbah 4:12; Tanhuma, Balak 16; Mekhilta on Exodus 12:6 (Bo, par. 5); Torah Shelemah on Exodus 1:1, vol. 8 p. 9 n. 26. , Midrash Lekach Tov on Exodus 6:6; Torah Shelemah, vol. 8 addenda ch. 3 p. 239.)
The Maharal explains that Jews did not change their names in Egypt, prior to receiving the Torah, but there is no prohibition to do so subsequently (N"Y 43).
See Gittin 11a and 11b that there were names that Jews never used. In Eretz Yisroel the only examples of such names that are quoted are: Louis and Lucas.
As is well known, Jews did use non-Jewish names throughout the Hellenistic period and beyond. Some of Babylonian Amoraim had Aramecaized names, for example, Rafram = R. Ephrem. What surprised me recently, however, was to learn that some of the Amoraim in the Yerushalmi also used Greek and Latin names.
Alexandroi - Brochos 2:4
Nikomachi - Moed Koton 1:5
Avmakhis - Sanhedrin 3"12
Justi - Eiruvin 6:4
Justini - B"B 8:5
Luliani - Yoma 2:2
Then there is R. Krispa and Kruspedai. In light of the above, may this be a contraction and adaptation, or a deliberate change, of Christopher - not at all a Jewish name.
Here is something that I found posted by Yisrael Dubitsky that speculates on Kruspedai:
According to the Arukh, it is possible that he was so named because he
was especially diligent WRT the mitsvah of tsitsit. Further, as there
was an individual named "Ben Tsitsit" [e.g. Bereshit Rabbah 42:1; Gittin
56a; see the gemara there as to why he was so named but see my comments
further] there is good reason to assume that Kruspadai is the translation
of such. In other places in Hazal his name appears as Krispa, Kruspa
or some such, which suggests to A. Kohut that it was intended to mimic
(?) the secular Greek name Crispus [funny how different threads of Avodah
are so often intertwined!], meaning curly haired. Which might shed light
on the physical description of our Amora in question.
Speaking of which, the gemara in Gittin explains the meaning of Ben
Tsitsit's name: it says "she-haytah tsitsato nigreret al gabei [karim
u-]kesatot". Rashi, in explaining the word tsitsato assumes it means
his talit, the fringes of which shlepped on "cushions of fine fabric,"
because, to quote Artscroll [Soncino, btw, explains it similarly], he was
so rich that "he walked only on cushions fashioned from fine fabric." Ah,
say I, that's fine and good for Rashi to say but now that we know a Greek
word which explains Kruspadai, which might have translated Ben Tsistit
to begin with, one is tempted to explain the gemara's explanation of the
name differently. Namely, it was his long curly *hair*[= tsistit means
fringes, sometimes of human hair; see Yehezkel 8:3], a style of the rich
back then, that shlepped/draped over karim u-kesatot as he *sat*, not