Homomorphic encryption is a cryptographic technique that allows data to be stored, accessed and manipulated while encrypted. Homomorphic encryption enables computations to be performed on ciphertexts, generating an encrypted result that, when decrypted, matches the result of the operations as if they had been performed on the plaintext. Homomorphic encryption can prevent the cloud service provider from being able to decipher the data due to its sensitivity, as the data remains encrypted at all times. Homomorphic encryption is not concerned about computational overheads and slow speeds, as it trades off performance for security and privacy. Reference:
https://www.professormesser.com/security-plus/sy0-601/sy0-601-video/cryptography-concepts-2/
https://www.microsoft.com/en-us/research/wp-content/uploads/2018/01/security_homomorphic_encryption_white_paper.pdf
https://www.professormesser.com/security-plus/sy0-601/sy0-601-video/symmetric-and-asymmetric-cryptography/