Number encryption algorithm

I have a list of numbers. I will be calling a service(let’s say accountant service) which is going to perform some operation on these list of numbers and will return me the final result.

I don’t want to pass my data in plain format. I want to encrypt numbers in such a way if service performs any arithmetic operation and return me the result, I will be able to decrypt it back with actual result.

I think what you are looking for is Homomorphic encryption. Basically, it performs operations on encrypted text, which can then be decrypted to obtain final result. For more info you can google it or you can look up wikipedia for further info.

Hope it helps