Fully Homomorphic Encryption (FHE) supports arbitary operations on encryption data without private key information. Because encrypted data should be decrypted for computations, secret key has to be stored in same place and this harms privacy in many applications. With FHE scheme, secret key is not need with the operations on encrypted data. This powerful property leads us to privacy preserving in various applications. However, inefficiency of the scheme makes it hard to apply in real world. In this talk, I will introduce various new algorithms for faster fully homomorphic encryption scheme. I will also show successful applications and experimental results in discrete Fourier transformation, logistic regression, and drone system on encrypted data (or signal).