Operations

Inco Lightning provides arithmetic, comparison, and bitwise operations on encrypted values.

Arithmetic Operations

All arithmetic operations return an Euint128.

Function	Description	Signature
`e_add`	Addition	`(Euint128, Euint128) -> Euint128`
`e_sub`	Subtraction	`(Euint128, Euint128) -> Euint128`
`e_mul`	Multiplication	`(Euint128, Euint128) -> Euint128`
`e_rem`	Remainder	`(Euint128, Euint128) -> Euint128`

Example: Encrypted Addition

pub fn add_balances(
    ctx: Context<AddBalances>,
    amount_a: Euint128,
    amount_b: Euint128,
) -> Result<()> {
    let cpi_ctx = CpiContext::new(
        ctx.accounts.inco_lightning_program.to_account_info(),
        Operation {
            signer: ctx.accounts.authority.to_account_info(),
        },
    );

    // Add two encrypted values
    let result: Euint128 = e_add(cpi_ctx, amount_a, amount_b, 0)?;

    ctx.accounts.account.total = result;

    // IMPORTANT: After storing the result handle, grant decryption access
    // to the appropriate address (e.g., owner) using the `allow` function.
    // See the Access Control guide for details.

    Ok(())
}

Comparison Operations

Comparison operations return an Ebool.

Function	Description	Signature
`e_ge`	Greater than or equal	`(Euint128, Euint128) -> Ebool`
`e_gt`	Greater than	`(Euint128, Euint128) -> Ebool`
`e_le`	Less than or equal	`(Euint128, Euint128) -> Ebool`
`e_lt`	Less than	`(Euint128, Euint128) -> Ebool`
`e_eq`	Equal	`(Euint128, Euint128) -> Ebool`

Bitwise Operations

Function	Description	Signature
`e_and`	Bitwise AND	`(Euint128, Euint128) -> Euint128`
`e_or`	Bitwise OR	`(Euint128, Euint128) -> Euint128`
`e_not`	Bitwise NOT	`(Euint128) -> Euint128`
`e_shl`	Shift left	`(Euint128, Euint128) -> Euint128`
`e_shr`	Shift right	`(Euint128, Euint128) -> Euint128`

CPI Context Pattern

All operations require a CPI context with the Inco Lightning program:

let cpi_ctx = CpiContext::new(
    ctx.accounts.inco_lightning_program.to_account_info(),
    Operation {
        signer: ctx.accounts.authority.to_account_info(),
    },
);

let result = e_add(cpi_ctx, a, b, 0)?;

// IMPORTANT: Define allowance rules after each operation that produces
// a handle you want to decrypt later. See Access Control guide.

The last parameter in operation calls identifies whether the left-hand side operand is ciphertext (0) or plaintext (1). Always pass 0 when working with encrypted handles.

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