A Secure Recommendation System for Providing Context-Aware Physical Activity Classification for Users

Table 2

Parameters of HE.

Notations	Description
UIDp	User_ID of a Person p
Mrkp(t)	Signature of person “p” on “t”
EC(K, t)	Pub_Key_Encryption on PT with key K
	HE on text “t” with key K
P(Kpub)	Person P’s Pub_Key
P (Ksec)	Person P’s secret key
Ep(t)	Person P’s encrypted Data
T	Time
Fp(AP)	Formalized value of person P’s mobile app access patterns
FP(UT)	Formalized value of person P’s mobile app usage time
FP(PA)	Formalized value of person P’s PA