Operations on encrypted types

The TFHE library defines the following operations with FHE ciphertexts:

name	function name	symbol	type
Add	TFHE.add	+	Binary
Sub	TFHE.sub	-	Binary
Mul	TFHE.mul	*	Binary
Div (plaintext divisor)	TFHE.div		Binary
Rem (plaintext divisor)	TFHE.rem		Binary
BitAnd	TFHE.and	&	Binary
BitOr	TFHE.or	|	Binary
BitXor	TFHE.xor	^	Binary
Shift Right	TFHE.shr		Binary
Shift Left	TFHE.shl		Binary
Rotate Right	TFHE.rotr		Binary
Rotate Left	TFHE.rotl		Binary
Equal	TFHE.eq		Binary
Not equal	TFHE.ne		Binary
Greater than or equal	TFHE.ge		Binary
Greater than	TFHE.gt		Binary
Less than or equal	TFHE.le		Binary
Less than	TFHE.lt		Binary
Min	TFHE.min		Binary
Max	TFHE.max		Binary
Neg	TFHE.neg	-	Unary
Not	TFHE.not	~	Unary
Select	TFHE.select		Ternary
Random unsigned int	TFHE.randEuintX()		Random

NOTE: The shift operators TFHE.shr and TFHE.shl can take any encrypted type euintX as a first operand and either a uint8or a euint8 as a second operand, however the second operand will always be computed modulo the number of bits of the first operand. For example, TFHE.shr(euint64 x, 70) will actually be equal to TFHE.shr(euint64 x, 6) because 70 % 64 = 6. This is in contrast to the classical shift operators in Solidity where there is no intermediate modulo operation, so for instance any uint64 shifted right via >> would give a null result.

Overloaded operators +, -, *, &, ... on encrypted integers are supported (using for). As of now, overloaded operators will call the versions without an overflow check.

More information about the supported operations can be found in the function specifications page or in the TFHE-rs docs.

If you find yourself in search of a missing feature, we encourage you to consult our roadmap for upcoming developments. Alternatively, don't hesitate to reach out to us on Discord or visit our community forum.

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