fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda > Class Template Reference

2-party VDMPF scheme. More...

Classes
struct	BucketKey
	Per-bucket key containing the inner VDPF key data. More...
struct	Key
	VDMPF key for one party. More...

Public Types
using	InnerVdpf = Vdpf< bucket_bits, Group, Prg, XorHash, Hash, uint >

Public Member Functions
int	Gen (Key &k0, Key &k1, int4 sigma, cuda::std::span< const cuda::std::array< int4, 2 >, m > s0s, std::span< const In > as, std::span< const int4 > b_bufs, int t, int ch_retry=1000)
	Key generation method.
void	BatchEval (bool b, const Key &key, std::span< const In > xs, std::span< int4 > ys, cuda::std::array< int4, 4 > &pi)
	Batch verifiable evaluation method.

Static Public Member Functions
static bool	Verify (cuda::std::span< const int4, 4 > pi0, cuda::std::span< const int4, 4 > pi1)
	Verification method.

Public Attributes
Prg	prg
XorHash	xor_hash
Hash	hash
Prp	prp

Static Public Attributes
static constexpr int	m = cuckoo_hash::ChBucket(max_points, ch_lambda)
static constexpr __uint128_t	n = __uint128_t(1) << in_bits
static constexpr int	b_size

Detailed Description

template<int in_bits, int max_points, int bucket_bits, typename Group, typename Prg, typename XorHash, typename Hash, typename Prp, typename In = uint, int kappa = 3, int ch_lambda = 80>
requires ((std::is_unsigned_v<In> || std::is_same_v<In, __uint128_t>) && in_bits <= sizeof(In) * 8 && Groupable<Group> && Prgable<Prg, 2> && XorHashable<XorHash> && Hashable<Hash> && Permutable<Prp>)
class fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda >

2-party VDMPF scheme.

Template Parameters

in_bits	Input domain bit size.
max_points	Maximum number of point functions. Must be >= 30. Sizes arrays at compile time.
bucket_bits	Bit size of the inner VDPF domain (per bucket).
Group	Type for the output domain. See Groupable.
Prg	See Prgable.
XorHash	See XorHashable. Paper's \(H\): maps \((x, s)\) to \(4\lambda\) bits.
Hash	See Hashable. Paper's \(H'\): maps \(4\lambda\) bits to \(2\lambda\) bits.
Prp	See Permutable. Used for Cuckoo hashing.
In	Type for the input domain. From uint8_t to __uint128_t.
kappa	Number of Cuckoo hash functions. 3 is good enough for all practical use cases (Lemma 5 and Remark 1 of the paper).
ch_lambda	Cuckoo-hashing security parameter in bits. Controls the failure probability of Cuckoo hashing: inserting t elements fails with probability at most \(2^{-\text{ch\_lambda}}\).

Member Function Documentation

BatchEval()

template<int in_bits, int max_points, int bucket_bits, typename Group , typename Prg , typename XorHash , typename Hash , typename Prp , typename In = uint, int kappa = 3, int ch_lambda = 80>

void fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda >::BatchEval ( bool  b, const Key &  key, std::span< const In >  xs, std::span< int4 >  ys, cuda::std::array< int4, 4 > &  pi  )

inline

Batch verifiable evaluation method.

Evaluates the VDMPF key on a batch of input points and produces output shares and a proof.

Parameters

b	Party index. False for 0 and true for 1.
key	This party's key.
xs	Input points to evaluate.
ys	Output shares (pre-allocated, size >= xs.size()). Will be zero-initialized.
pi	Proof output.

Gen()

template<int in_bits, int max_points, int bucket_bits, typename Group , typename Prg , typename XorHash , typename Hash , typename Prp , typename In = uint, int kappa = 3, int ch_lambda = 80>

int fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda >::Gen ( Key &  k0, Key &  k1, int4  sigma, cuda::std::span< const cuda::std::array< int4, 2 >, m >  s0s, std::span< const In >  as, std::span< const int4 >  b_bufs, int  t, int  ch_retry = 1000  )

inline

Key generation method.

Parameters

k0	Key output for party 0.
k1	Key output for party 1.
sigma	PRP seed. Users can randomly sample it.
s0s	m pairs of initial seeds for inner VDPFs. Users can randomly sample them.
as	Alpha values of t point functions.
b_bufs	Corresponding beta values. Will be clamped.
t	Actual number of points (<= max_points).
ch_retry	Max Cuckoo hash eviction attempts.

Returns

0 on success, 1 on failure (Cuckoo hash or inner VDPF Gen failed).

Verify()

template<int in_bits, int max_points, int bucket_bits, typename Group , typename Prg , typename XorHash , typename Hash , typename Prp , typename In = uint, int kappa = 3, int ch_lambda = 80>

static bool fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda >::Verify ( cuda::std::span< const int4, 4 >  pi0, cuda::std::span< const int4, 4 >  pi1  )

inlinestatic

Verification method.

Returns

True if proofs match (Accept), false otherwise (Reject).

Member Data Documentation

b_size

template<int in_bits, int max_points, int bucket_bits, typename Group , typename Prg , typename XorHash , typename Hash , typename Prp , typename In = uint, int kappa = 3, int ch_lambda = 80>

constexpr int fss::Vdmpf< in_bits, max_points, bucket_bits, Group, Prg, XorHash, Hash, Prp, In, kappa, ch_lambda >::b_size

staticconstexpr

Initial value:

=
        static_cast<int>((static_cast<__uint128_t>(n) * kappa + m - 1) / m)

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The documentation for this class was generated from the following file:

• include/fss/vdmpf.cuh