One related concept is “partially homomorphic encryption” (https://en.wikipedia.org/wiki/Homomorphic_encryption#Partially_homomorphic_cryptosystems https://en.w

One related concept is “partially homomorphic encryption” (https://en.wikipedia.org/wiki/Homomorphic_encryption#Partially_homomorphic_cryptosystems https://en.wikipedia.org/wiki/Homomorphic_encryption#Partial...). These are encryption schemes that are homomorphic under one operation such as addition or multiplication. For example, you could use an additively homomorphic scheme to compute a sum of encrypted values. This could then be converted into an average assuming you knew the number of values.