Table 2.

Degree of integration for typical integrated QKD implementations

Reference	Platform	Protocol	QRNG	Source	Encoding	Decoding	Detector
Sibson, P. et al. (2017)42	InP, SiOxNy	BB84 COW DPS	No	Yes	Yes	Yes	No
Paraïso, T. K. et al. (2019)153	InP	DPS BB84	Yes	Yes	Yes	No	No
Paraïso, T. K. et al. (2021)154	InP, Si	Modified BB84	Yes	Yes	Yes	Yes	No
Ma, C. et al. (2016)95	Si	BB84	No	No	Yes	No	No
Sibson, P. et al. (2017)155	Si, SiOxNy	COW BB84	No	No	Yes	Yes	No
Bunandar, D. et al. (2018)157	Si	BB84	No	No	Yes	No	No
Avesani, M. et al. (2021)158	Si	BB84	No	No	Yes	No	No
Geng, W. et al. (2019)159	Si	BB84	No	No	Yes	Yes	No
Dai, J. et al. (2020)160	Si	COW DPS	No	No	Yes	Yes	No
Ding, Y. et al. (2017)162	Si	HD-QKD	No	No	Yes	Yes	No
Semenenko, H. et al. (2020)81	InP	MDI-QKD	No	Yes	Yes	No	No
Wei, K. et al. (2020)94	Si	MDI-QKD	No	No	Yes	No	No
Cao, L. et al. (2020)96	Si	MDI-QKD	No	No	Yes	Yes	No
Zheng, X. et al. (2021)165	Si, NbN	MDI-QKD	No	No	No	Yes	Yes
Zhang, G. et al. (2019)43	Si	CV-QKD	No	No	Yes	Yes	Yes

COW coherent one way, DPS differential phase shift, HD-QKD high-dimensional QKD