> ## Documentation Index
> Fetch the complete documentation index at: https://docs.inco.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Input & Encryption

> How to encrypt input data for Solana programs

# Input & Encryption

To create an encrypted value, use `new_euint128` or `new_ebool` with client-encrypted ciphertext.

## Creating Encrypted Values (Program Side)

```rust theme={null}
pub fn deposit(
    ctx: Context<Deposit>,
    ciphertext: Vec<u8>,  // Client-encrypted amount
) -> Result<()> {
    // Create CPI context
    let cpi_ctx = CpiContext::new(
        ctx.accounts.inco_lightning_program.to_account_info(),
        Operation {
            signer: ctx.accounts.authority.to_account_info(),
        },
    );

    // Create encrypted handle from ciphertext
    let encrypted_amount: Euint128 = new_euint128(cpi_ctx, ciphertext, 0)?;

    // Store the handle
    ctx.accounts.vault.balance = encrypted_amount;

    // IMPORTANT: After creating a new handle, grant decryption access
    // to the appropriate address using the `allow` function.
    // See the Access Control guide for details.

    Ok(())
}
```

## Input Functions

| Function       | Description                                                  | Signature                                       |
| -------------- | ------------------------------------------------------------ | ----------------------------------------------- |
| `new_euint128` | Create encrypted u128 from client-encrypted ciphertext       | `(CpiContext, Vec<u8>, u8) -> Result<Euint128>` |
| `new_ebool`    | Create encrypted bool from client-encrypted ciphertext       | `(CpiContext, Vec<u8>, u8) -> Result<Ebool>`    |
| `as_euint128`  | Convert plaintext u128 to encrypted handle (trivial encrypt) | `(CpiContext, u128) -> Result<Euint128>`        |
| `as_ebool`     | Convert plaintext bool to encrypted handle (trivial encrypt) | `(CpiContext, bool) -> Result<Ebool>`           |

<Note>
  The last parameter in `new_euint128`/`new_ebool` identifies whether the input is ciphertext (`0`) or plaintext (`1`). Always pass `0` when working with client-encrypted data.
</Note>

## Trivial Encryption

Use `as_euint128` and `as_ebool` to convert plaintext values to encrypted handles directly in your program. This is useful for constants or program-generated values.

```rust theme={null}
pub fn initialize_with_zero(
    ctx: Context<Initialize>,
) -> Result<()> {
    let cpi_ctx = CpiContext::new(
        ctx.accounts.inco_lightning_program.to_account_info(),
        Operation {
            signer: ctx.accounts.authority.to_account_info(),
        },
    );

    // Create encrypted zero
    let zero: Euint128 = as_euint128(cpi_ctx, 0)?;

    ctx.accounts.account.balance = zero;

    // IMPORTANT: Grant decryption access to the owner if this handle
    // needs to be decrypted later. See Access Control guide.

    Ok(())
}
```

<Warning>
  Trivial encryption should only be used for public constants (like zero) or values that don't need to be secret. For user-provided sensitive values, always use client-side encryption with `new_euint128`.
</Warning>

## Client-Side Encryption

Values must be encrypted client-side before sending to your program. Use the [JavaScript SDK](/svm/js-sdk/encryption) to encrypt values:

```typescript theme={null}
import { encryptValue } from '@inco/solana-sdk/encryption';

const encrypted = await encryptValue(100n);
await program.methods
  .deposit(Buffer.from(encrypted, 'hex'))
  .rpc();
```

<Note>
  See the [JavaScript SDK Encryption documentation](/svm/js-sdk/encryption) for supported types and error handling.
</Note>