# TFHE Basic Operations

This section introduces the **basic homomorphic operations** you’ll use constantly in TFHE :

* **Homomorphic addition** (ciphertext + ciphertext)
* **Homomorphic addition with a constant** (ciphertext + clear value)
* **Homomorphic multiplication by a small constant polynomial** (ciphertext × clear polynomial)

These operations are called **linear operations** because they don’t require bootstrapping by themselves and they behave “nicely” with noise (it grows predictably). They are also the building blocks for more advanced TFHE primitives like key switching, external product, CMux, and bootstrapping.

> We keep the focus here on **(G)LWE-style ciphertexts** (LWE, RLWE/GLWE), since TFHE builds everything on top of them.

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