Analysis of information sources in references of the Wikipedia article "Cross" in English language version.
The jurist Julius Paulus, for example, "gives crucifixion (furca = gallows, the word that replaced the 'holy' word cross in legal literature after Constantine)" as one punishment for deserters and for betrayers of secrets (Hengel 1977:39; Bauman 1996:151)
According to the article "crux" in Pauly-Wissowa, the old term furca may have been revived under Justinian to shield the sacred term from misuse; its shape, the conventional 'gallows', may have been evolved in such a way as to avoid any association with the Christian cross.
The cross as a Christian symbol or "seal" came into use at least as early since the 2nd century AD (see "Apost. Const." iii. 17; Epistle of Barnabas, xi.-xii.; Justin, "Apologia," i. 55-60; "Dial. cum Tryph." 85-97); and the marking of a cross upon the forehead and the chest was regarded as a talisman against the powers of demons (Tertullian, "De Corona," iii.; Cyprian, "Testimonies," xi. 21-22; Lactantius, "Divinæ Institutiones," iv. 27, and elsewhere). Accordingly the Christian Fathers had to defend themselves, as early as the second century, against the charge of being worshipers of the cross, as may be learned from Tertullian, "Apologia," xii., xvii., and Minucius Felix, "Octavius," xxix. Christians used to swear by the power of the cross
Then, if any of you think we render superstitious adoration to the cross, in that adoration he is sharer with us. If you offer homage to a piece of wood at all, it matters little what it is like when the substance is the same: it is of no consequence the form, if you have the very body of the god. And yet how far does the Athenian Pallas differ from the stock of the cross, or the Pharian Ceres as she is put up uncarved to sale, a mere rough stake and piece of shapeless wood? Every stake fixed in an upright position is a portion of the cross; we render our adoration, if you will have it so, to a god entire and complete. We have shown before that your deities are derived from shapes modelled from the cross.Sed et qui crucis nos religiosos putat, consecraneus noster erit. Cum lignum aliquod propitiatur, viderit habitus, dum materiae qualitas eadem sit; viderit forma, dum id ipsum dei corpus sit. Et tamen quanto distinguitur a crucis stipite Pallas Attica, et Ceres Pharia, quae sine effigie rudi palo et informi ligno prostat? Pars crucis est omne robur, quod erecta statione defigitur; nos, si forte, integrum et totum deum colimus. Diximus originem deorum vestrorum a plastis de cruce induci.
The cross as a Christian symbol or "seal" came into use at least as early since the 2nd century AD (see "Apost. Const." iii. 17; Epistle of Barnabas, xi.-xii.; Justin, "Apologia," i. 55-60; "Dial. cum Tryph." 85-97); and the marking of a cross upon the forehead and the chest was regarded as a talisman against the powers of demons (Tertullian, "De Corona," iii.; Cyprian, "Testimonies," xi. 21-22; Lactantius, "Divinæ Institutiones," iv. 27, and elsewhere). Accordingly the Christian Fathers had to defend themselves, as early as the second century, against the charge of being worshipers of the cross, as may be learned from Tertullian, "Apologia," xii., xvii., and Minucius Felix, "Octavius," xxix. Christians used to swear by the power of the cross
Then, if any of you think we render superstitious adoration to the cross, in that adoration he is sharer with us. If you offer homage to a piece of wood at all, it matters little what it is like when the substance is the same: it is of no consequence the form, if you have the very body of the god. And yet how far does the Athenian Pallas differ from the stock of the cross, or the Pharian Ceres as she is put up uncarved to sale, a mere rough stake and piece of shapeless wood? Every stake fixed in an upright position is a portion of the cross; we render our adoration, if you will have it so, to a god entire and complete. We have shown before that your deities are derived from shapes modelled from the cross.Sed et qui crucis nos religiosos putat, consecraneus noster erit. Cum lignum aliquod propitiatur, viderit habitus, dum materiae qualitas eadem sit; viderit forma, dum id ipsum dei corpus sit. Et tamen quanto distinguitur a crucis stipite Pallas Attica, et Ceres Pharia, quae sine effigie rudi palo et informi ligno prostat? Pars crucis est omne robur, quod erecta statione defigitur; nos, si forte, integrum et totum deum colimus. Diximus originem deorum vestrorum a plastis de cruce induci.