arnaucube
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miden-crypto/src/hash/rpo/mod.rs
src/hash/rpo/mod.rsRaw
  1use super::{Digest, ElementHasher, Felt, FieldElement, Hasher, StarkField, ONE, ZERO};
  2use core::{convert::TryInto, ops::Range};
  3
  4mod digest;
  5pub use digest::RpoDigest;
  6
  7mod mds_freq;
  8use mds_freq::mds_multiply_freq;
  9
 10#[cfg(test)]
 11mod tests;
 12
 13#[cfg(all(target_feature = "sve", feature = "sve"))]
 14#[link(name = "rpo_sve", kind = "static")]
 15extern "C" {
 16    fn add_constants_and_apply_sbox(
 17        state: *mut std::ffi::c_ulong,
 18        constants: *const std::ffi::c_ulong,
 19    ) -> bool;
 20    fn add_constants_and_apply_inv_sbox(
 21        state: *mut std::ffi::c_ulong,
 22        constants: *const std::ffi::c_ulong,
 23    ) -> bool;
 24}
 25
 26// CONSTANTS
 27// ================================================================================================
 28
 29/// Sponge state is set to 12 field elements or 96 bytes; 8 elements are reserved for rate and
 30/// the remaining 4 elements are reserved for capacity.
 31const STATE_WIDTH: usize = 12;
 32
 33/// The rate portion of the state is located in elements 4 through 11.
 34const RATE_RANGE: Range<usize> = 4..12;
 35const RATE_WIDTH: usize = RATE_RANGE.end - RATE_RANGE.start;
 36
 37const INPUT1_RANGE: Range<usize> = 4..8;
 38const INPUT2_RANGE: Range<usize> = 8..12;
 39
 40/// The capacity portion of the state is located in elements 0, 1, 2, and 3.
 41const CAPACITY_RANGE: Range<usize> = 0..4;
 42
 43/// The output of the hash function is a digest which consists of 4 field elements or 32 bytes.
 44///
 45/// The digest is returned from state elements 4, 5, 6, and 7 (the first four elements of the
 46/// rate portion).
 47const DIGEST_RANGE: Range<usize> = 4..8;
 48const DIGEST_SIZE: usize = DIGEST_RANGE.end - DIGEST_RANGE.start;
 49
 50/// The number of rounds is set to 7 to target 128-bit security level
 51const NUM_ROUNDS: usize = 7;
 52
 53/// The number of byte chunks defining a field element when hashing a sequence of bytes
 54const BINARY_CHUNK_SIZE: usize = 7;
 55
 56/// S-Box and Inverse S-Box powers;
 57///
 58/// The constants are defined for tests only because the exponentiations in the code are unrolled
 59/// for efficiency reasons.
 60#[cfg(test)]
 61const ALPHA: u64 = 7;
 62#[cfg(test)]
 63const INV_ALPHA: u64 = 10540996611094048183;
 64
 65// HASHER IMPLEMENTATION
 66// ================================================================================================
 67
 68/// Implementation of the Rescue Prime Optimized hash function with 256-bit output.
 69///
 70/// The hash function is implemented according to the Rescue Prime Optimized
 71/// [specifications](https://eprint.iacr.org/2022/1577)
 72///
 73/// The parameters used to instantiate the function are:
 74/// * Field: 64-bit prime field with modulus 2^64 - 2^32 + 1.
 75/// * State width: 12 field elements.
 76/// * Capacity size: 4 field elements.
 77/// * Number of founds: 7.
 78/// * S-Box degree: 7.
 79///
 80/// The above parameters target 128-bit security level. The digest consists of four field elements
 81/// and it can be serialized into 32 bytes (256 bits).
 82///
 83/// ## Hash output consistency
 84/// Functions [hash_elements()](Rpo256::hash_elements), [merge()](Rpo256::merge), and
 85/// [merge_with_int()](Rpo256::merge_with_int) are internally consistent. That is, computing
 86/// a hash for the same set of elements using these functions will always produce the same
 87/// result. For example, merging two digests using [merge()](Rpo256::merge) will produce the
 88/// same result as hashing 8 elements which make up these digests using
 89/// [hash_elements()](Rpo256::hash_elements) function.
 90///
 91/// However, [hash()](Rpo256::hash) function is not consistent with functions mentioned above.
 92/// For example, if we take two field elements, serialize them to bytes and hash them using
 93/// [hash()](Rpo256::hash), the result will differ from the result obtained by hashing these
 94/// elements directly using [hash_elements()](Rpo256::hash_elements) function. The reason for
 95/// this difference is that [hash()](Rpo256::hash) function needs to be able to handle
 96/// arbitrary binary strings, which may or may not encode valid field elements - and thus,
 97/// deserialization procedure used by this function is different from the procedure used to
 98/// deserialize valid field elements.
 99///
100/// Thus, if the underlying data consists of valid field elements, it might make more sense
101/// to deserialize them into field elements and then hash them using
102/// [hash_elements()](Rpo256::hash_elements) function rather then hashing the serialized bytes
103/// using [hash()](Rpo256::hash) function.
104#[derive(Debug, Copy, Clone, Eq, PartialEq)]
105pub struct Rpo256();
106
107impl Hasher for Rpo256 {
108    /// Rpo256 collision resistance is the same as the security level, that is 128-bits.
109    ///
110    /// #### Collision resistance
111    ///
112    /// However, our setup of the capacity registers might drop it to 126.
113    ///
114    /// Related issue: [#69](https://github.com/0xPolygonMiden/crypto/issues/69)
115    const COLLISION_RESISTANCE: u32 = 128;
116
117    type Digest = RpoDigest;
118
119    fn hash(bytes: &[u8]) -> Self::Digest {
120        // initialize the state with zeroes
121        let mut state = [ZERO; STATE_WIDTH];
122
123        // set the capacity (first element) to a flag on whether or not the input length is evenly
124        // divided by the rate. this will prevent collisions between padded and non-padded inputs,
125        // and will rule out the need to perform an extra permutation in case of evenly divided
126        // inputs.
127        let is_rate_multiple = bytes.len() % RATE_WIDTH == 0;
128        if !is_rate_multiple {
129            state[CAPACITY_RANGE.start] = ONE;
130        }
131
132        // initialize a buffer to receive the little-endian elements.
133        let mut buf = [0_u8; 8];
134
135        // iterate the chunks of bytes, creating a field element from each chunk and copying it
136        // into the state.
137        //
138        // every time the rate range is filled, a permutation is performed. if the final value of
139        // `i` is not zero, then the chunks count wasn't enough to fill the state range, and an
140        // additional permutation must be performed.
141        let i = bytes.chunks(BINARY_CHUNK_SIZE).fold(0, |i, chunk| {
142            // the last element of the iteration may or may not be a full chunk. if it's not, then
143            // we need to pad the remainder bytes of the chunk with zeroes, separated by a `1`.
144            // this will avoid collisions.
145            if chunk.len() == BINARY_CHUNK_SIZE {
146                buf[..BINARY_CHUNK_SIZE].copy_from_slice(chunk);
147            } else {
148                buf.fill(0);
149                buf[..chunk.len()].copy_from_slice(chunk);
150                buf[chunk.len()] = 1;
151            }
152
153            // set the current rate element to the input. since we take at most 7 bytes, we are
154            // guaranteed that the inputs data will fit into a single field element.
155            state[RATE_RANGE.start + i] = Felt::new(u64::from_le_bytes(buf));
156
157            // proceed filling the range. if it's full, then we apply a permutation and reset the
158            // counter to the beginning of the range.
159            if i == RATE_WIDTH - 1 {
160                Self::apply_permutation(&mut state);
161                0
162            } else {
163                i + 1
164            }
165        });
166
167        // if we absorbed some elements but didn't apply a permutation to them (would happen when
168        // the number of elements is not a multiple of RATE_WIDTH), apply the RPO permutation. we
169        // don't need to apply any extra padding because the first capacity element contains a
170        // flag indicating whether the input is evenly divisible by the rate.
171        if i != 0 {
172            state[RATE_RANGE.start + i..RATE_RANGE.end].fill(ZERO);
173            state[RATE_RANGE.start + i] = ONE;
174            Self::apply_permutation(&mut state);
175        }
176
177        // return the first 4 elements of the rate as hash result.
178        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
179    }
180
181    fn merge(values: &[Self::Digest; 2]) -> Self::Digest {
182        // initialize the state by copying the digest elements into the rate portion of the state
183        // (8 total elements), and set the capacity elements to 0.
184        let mut state = [ZERO; STATE_WIDTH];
185        let it = Self::Digest::digests_as_elements(values.iter());
186        for (i, v) in it.enumerate() {
187            state[RATE_RANGE.start + i] = *v;
188        }
189
190        // apply the RPO permutation and return the first four elements of the state
191        Self::apply_permutation(&mut state);
192        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
193    }
194
195    fn merge_with_int(seed: Self::Digest, value: u64) -> Self::Digest {
196        // initialize the state as follows:
197        // - seed is copied into the first 4 elements of the rate portion of the state.
198        // - if the value fits into a single field element, copy it into the fifth rate element
199        //   and set the sixth rate element to 1.
200        // - if the value doesn't fit into a single field element, split it into two field
201        //   elements, copy them into rate elements 5 and 6, and set the seventh rate element
202        //   to 1.
203        // - set the first capacity element to 1
204        let mut state = [ZERO; STATE_WIDTH];
205        state[INPUT1_RANGE].copy_from_slice(seed.as_elements());
206        state[INPUT2_RANGE.start] = Felt::new(value);
207        if value < Felt::MODULUS {
208            state[INPUT2_RANGE.start + 1] = ONE;
209        } else {
210            state[INPUT2_RANGE.start + 1] = Felt::new(value / Felt::MODULUS);
211            state[INPUT2_RANGE.start + 2] = ONE;
212        }
213
214        // common padding for both cases
215        state[CAPACITY_RANGE.start] = ONE;
216
217        // apply the RPO permutation and return the first four elements of the state
218        Self::apply_permutation(&mut state);
219        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
220    }
221}
222
223impl ElementHasher for Rpo256 {
224    type BaseField = Felt;
225
226    fn hash_elements<E: FieldElement<BaseField = Self::BaseField>>(elements: &[E]) -> Self::Digest {
227        // convert the elements into a list of base field elements
228        let elements = E::slice_as_base_elements(elements);
229
230        // initialize state to all zeros, except for the first element of the capacity part, which
231        // is set to 1 if the number of elements is not a multiple of RATE_WIDTH.
232        let mut state = [ZERO; STATE_WIDTH];
233        if elements.len() % RATE_WIDTH != 0 {
234            state[CAPACITY_RANGE.start] = ONE;
235        }
236
237        // absorb elements into the state one by one until the rate portion of the state is filled
238        // up; then apply the Rescue permutation and start absorbing again; repeat until all
239        // elements have been absorbed
240        let mut i = 0;
241        for &element in elements.iter() {
242            state[RATE_RANGE.start + i] = element;
243            i += 1;
244            if i % RATE_WIDTH == 0 {
245                Self::apply_permutation(&mut state);
246                i = 0;
247            }
248        }
249
250        // if we absorbed some elements but didn't apply a permutation to them (would happen when
251        // the number of elements is not a multiple of RATE_WIDTH), apply the RPO permutation after
252        // padding by appending a 1 followed by as many 0 as necessary to make the input length a
253        // multiple of the RATE_WIDTH.
254        if i > 0 {
255            state[RATE_RANGE.start + i] = ONE;
256            i += 1;
257            while i != RATE_WIDTH {
258                state[RATE_RANGE.start + i] = ZERO;
259                i += 1;
260            }
261            Self::apply_permutation(&mut state);
262        }
263
264        // return the first 4 elements of the state as hash result
265        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
266    }
267}
268
269// HASH FUNCTION IMPLEMENTATION
270// ================================================================================================
271
272impl Rpo256 {
273    // CONSTANTS
274    // --------------------------------------------------------------------------------------------
275
276    /// The number of rounds is set to 7 to target 128-bit security level.
277    pub const NUM_ROUNDS: usize = NUM_ROUNDS;
278
279    /// Sponge state is set to 12 field elements or 768 bytes; 8 elements are reserved for rate and
280    /// the remaining 4 elements are reserved for capacity.
281    pub const STATE_WIDTH: usize = STATE_WIDTH;
282
283    /// The rate portion of the state is located in elements 4 through 11 (inclusive).
284    pub const RATE_RANGE: Range<usize> = RATE_RANGE;
285
286    /// The capacity portion of the state is located in elements 0, 1, 2, and 3.
287    pub const CAPACITY_RANGE: Range<usize> = CAPACITY_RANGE;
288
289    /// The output of the hash function can be read from state elements 4, 5, 6, and 7.
290    pub const DIGEST_RANGE: Range<usize> = DIGEST_RANGE;
291
292    /// MDS matrix used for computing the linear layer in a RPO round.
293    pub const MDS: [[Felt; STATE_WIDTH]; STATE_WIDTH] = MDS;
294
295    /// Round constants added to the hasher state in the first half of the RPO round.
296    pub const ARK1: [[Felt; STATE_WIDTH]; NUM_ROUNDS] = ARK1;
297
298    /// Round constants added to the hasher state in the second half of the RPO round.
299    pub const ARK2: [[Felt; STATE_WIDTH]; NUM_ROUNDS] = ARK2;
300
301    // TRAIT PASS-THROUGH FUNCTIONS
302    // --------------------------------------------------------------------------------------------
303
304    /// Returns a hash of the provided sequence of bytes.
305    #[inline(always)]
306    pub fn hash(bytes: &[u8]) -> RpoDigest {
307        <Self as Hasher>::hash(bytes)
308    }
309
310    /// Returns a hash of two digests. This method is intended for use in construction of
311    /// Merkle trees and verification of Merkle paths.
312    #[inline(always)]
313    pub fn merge(values: &[RpoDigest; 2]) -> RpoDigest {
314        <Self as Hasher>::merge(values)
315    }
316
317    /// Returns a hash of the provided field elements.
318    #[inline(always)]
319    pub fn hash_elements<E: FieldElement<BaseField = Felt>>(elements: &[E]) -> RpoDigest {
320        <Self as ElementHasher>::hash_elements(elements)
321    }
322
323    // DOMAIN IDENTIFIER
324    // --------------------------------------------------------------------------------------------
325
326    /// Returns a hash of two digests and a domain identifier.
327    pub fn merge_in_domain(values: &[RpoDigest; 2], domain: Felt) -> RpoDigest {
328        // initialize the state by copying the digest elements into the rate portion of the state
329        // (8 total elements), and set the capacity elements to 0.
330        let mut state = [ZERO; STATE_WIDTH];
331        let it = RpoDigest::digests_as_elements(values.iter());
332        for (i, v) in it.enumerate() {
333            state[RATE_RANGE.start + i] = *v;
334        }
335
336        // set the second capacity element to the domain value. The first capacity element is used
337        // for padding purposes.
338        state[CAPACITY_RANGE.start + 1] = domain;
339
340        // apply the RPO permutation and return the first four elements of the state
341        Self::apply_permutation(&mut state);
342        RpoDigest::new(state[DIGEST_RANGE].try_into().unwrap())
343    }
344
345    // RESCUE PERMUTATION
346    // --------------------------------------------------------------------------------------------
347
348    /// Applies RPO permutation to the provided state.
349    #[inline(always)]
350    pub fn apply_permutation(state: &mut [Felt; STATE_WIDTH]) {
351        for i in 0..NUM_ROUNDS {
352            Self::apply_round(state, i);
353        }
354    }
355
356    /// RPO round function.
357    #[inline(always)]
358    pub fn apply_round(state: &mut [Felt; STATE_WIDTH], round: usize) {
359        // apply first half of RPO round
360        Self::apply_mds(state);
361        if !Self::optimized_add_constants_and_apply_sbox(state, &ARK1[round]) {
362            Self::add_constants(state, &ARK1[round]);
363            Self::apply_sbox(state);
364        }
365
366        // apply second half of RPO round
367        Self::apply_mds(state);
368        if !Self::optimized_add_constants_and_apply_inv_sbox(state, &ARK2[round]) {
369            Self::add_constants(state, &ARK2[round]);
370            Self::apply_inv_sbox(state);
371        }
372    }
373
374    // HELPER FUNCTIONS
375    // --------------------------------------------------------------------------------------------
376
377    #[inline(always)]
378    #[cfg(all(target_feature = "sve", feature = "sve"))]
379    fn optimized_add_constants_and_apply_sbox(
380        state: &mut [Felt; STATE_WIDTH],
381        ark: &[Felt; STATE_WIDTH],
382    ) -> bool {
383        unsafe {
384            add_constants_and_apply_sbox(state.as_mut_ptr() as *mut u64, ark.as_ptr() as *const u64)
385        }
386    }
387
388    #[inline(always)]
389    #[cfg(not(all(target_feature = "sve", feature = "sve")))]
390    fn optimized_add_constants_and_apply_sbox(
391        _state: &mut [Felt; STATE_WIDTH],
392        _ark: &[Felt; STATE_WIDTH],
393    ) -> bool {
394        false
395    }
396
397    #[inline(always)]
398    #[cfg(all(target_feature = "sve", feature = "sve"))]
399    fn optimized_add_constants_and_apply_inv_sbox(
400        state: &mut [Felt; STATE_WIDTH],
401        ark: &[Felt; STATE_WIDTH],
402    ) -> bool {
403        unsafe {
404            add_constants_and_apply_inv_sbox(
405                state.as_mut_ptr() as *mut u64,
406                ark.as_ptr() as *const u64,
407            )
408        }
409    }
410
411    #[inline(always)]
412    #[cfg(not(all(target_feature = "sve", feature = "sve")))]
413    fn optimized_add_constants_and_apply_inv_sbox(
414        _state: &mut [Felt; STATE_WIDTH],
415        _ark: &[Felt; STATE_WIDTH],
416    ) -> bool {
417        false
418    }
419
420    #[inline(always)]
421    fn apply_mds(state: &mut [Felt; STATE_WIDTH]) {
422        let mut result = [ZERO; STATE_WIDTH];
423
424        // Using the linearity of the operations we can split the state into a low||high decomposition
425        // and operate on each with no overflow and then combine/reduce the result to a field element.
426        // The no overflow is guaranteed by the fact that the MDS matrix is a small powers of two in
427        // frequency domain.
428        let mut state_l = [0u64; STATE_WIDTH];
429        let mut state_h = [0u64; STATE_WIDTH];
430
431        for r in 0..STATE_WIDTH {
432            let s = state[r].inner();
433            state_h[r] = s >> 32;
434            state_l[r] = (s as u32) as u64;
435        }
436
437        let state_h = mds_multiply_freq(state_h);
438        let state_l = mds_multiply_freq(state_l);
439
440        for r in 0..STATE_WIDTH {
441            let s = state_l[r] as u128 + ((state_h[r] as u128) << 32);
442            let s_hi = (s >> 64) as u64;
443            let s_lo = s as u64;
444            let z = (s_hi << 32) - s_hi;
445            let (res, over) = s_lo.overflowing_add(z);
446
447            result[r] = Felt::from_mont(res.wrapping_add(0u32.wrapping_sub(over as u32) as u64));
448        }
449        *state = result;
450    }
451
452    #[inline(always)]
453    fn add_constants(state: &mut [Felt; STATE_WIDTH], ark: &[Felt; STATE_WIDTH]) {
454        state.iter_mut().zip(ark).for_each(|(s, &k)| *s += k);
455    }
456
457    #[inline(always)]
458    fn apply_sbox(state: &mut [Felt; STATE_WIDTH]) {
459        state[0] = state[0].exp7();
460        state[1] = state[1].exp7();
461        state[2] = state[2].exp7();
462        state[3] = state[3].exp7();
463        state[4] = state[4].exp7();
464        state[5] = state[5].exp7();
465        state[6] = state[6].exp7();
466        state[7] = state[7].exp7();
467        state[8] = state[8].exp7();
468        state[9] = state[9].exp7();
469        state[10] = state[10].exp7();
470        state[11] = state[11].exp7();
471    }
472
473    #[inline(always)]
474    fn apply_inv_sbox(state: &mut [Felt; STATE_WIDTH]) {
475        // compute base^10540996611094048183 using 72 multiplications per array element
476        // 10540996611094048183 = b1001001001001001001001001001000110110110110110110110110110110111
477
478        // compute base^10
479        let mut t1 = *state;
480        t1.iter_mut().for_each(|t| *t = t.square());
481
482        // compute base^100
483        let mut t2 = t1;
484        t2.iter_mut().for_each(|t| *t = t.square());
485
486        // compute base^100100
487        let t3 = Self::exp_acc::<Felt, STATE_WIDTH, 3>(t2, t2);
488
489        // compute base^100100100100
490        let t4 = Self::exp_acc::<Felt, STATE_WIDTH, 6>(t3, t3);
491
492        // compute base^100100100100100100100100
493        let t5 = Self::exp_acc::<Felt, STATE_WIDTH, 12>(t4, t4);
494
495        // compute base^100100100100100100100100100100
496        let t6 = Self::exp_acc::<Felt, STATE_WIDTH, 6>(t5, t3);
497
498        // compute base^1001001001001001001001001001000100100100100100100100100100100
499        let t7 = Self::exp_acc::<Felt, STATE_WIDTH, 31>(t6, t6);
500
501        // compute base^1001001001001001001001001001000110110110110110110110110110110111
502        for (i, s) in state.iter_mut().enumerate() {
503            let a = (t7[i].square() * t6[i]).square().square();
504            let b = t1[i] * t2[i] * *s;
505            *s = a * b;
506        }
507    }
508
509    #[inline(always)]
510    fn exp_acc<B: StarkField, const N: usize, const M: usize>(
511        base: [B; N],
512        tail: [B; N],
513    ) -> [B; N] {
514        let mut result = base;
515        for _ in 0..M {
516            result.iter_mut().for_each(|r| *r = r.square());
517        }
518        result.iter_mut().zip(tail).for_each(|(r, t)| *r *= t);
519        result
520    }
521}
522
523// MDS
524// ================================================================================================
525/// RPO MDS matrix
526const MDS: [[Felt; STATE_WIDTH]; STATE_WIDTH] = [
527    [
528        Felt::new(7),
529        Felt::new(23),
530        Felt::new(8),
531        Felt::new(26),
532        Felt::new(13),
533        Felt::new(10),
534        Felt::new(9),
535        Felt::new(7),
536        Felt::new(6),
537        Felt::new(22),
538        Felt::new(21),
539        Felt::new(8),
540    ],
541    [
542        Felt::new(8),
543        Felt::new(7),
544        Felt::new(23),
545        Felt::new(8),
546        Felt::new(26),
547        Felt::new(13),
548        Felt::new(10),
549        Felt::new(9),
550        Felt::new(7),
551        Felt::new(6),
552        Felt::new(22),
553        Felt::new(21),
554    ],
555    [
556        Felt::new(21),
557        Felt::new(8),
558        Felt::new(7),
559        Felt::new(23),
560        Felt::new(8),
561        Felt::new(26),
562        Felt::new(13),
563        Felt::new(10),
564        Felt::new(9),
565        Felt::new(7),
566        Felt::new(6),
567        Felt::new(22),
568    ],
569    [
570        Felt::new(22),
571        Felt::new(21),
572        Felt::new(8),
573        Felt::new(7),
574        Felt::new(23),
575        Felt::new(8),
576        Felt::new(26),
577        Felt::new(13),
578        Felt::new(10),
579        Felt::new(9),
580        Felt::new(7),
581        Felt::new(6),
582    ],
583    [
584        Felt::new(6),
585        Felt::new(22),
586        Felt::new(21),
587        Felt::new(8),
588        Felt::new(7),
589        Felt::new(23),
590        Felt::new(8),
591        Felt::new(26),
592        Felt::new(13),
593        Felt::new(10),
594        Felt::new(9),
595        Felt::new(7),
596    ],
597    [
598        Felt::new(7),
599        Felt::new(6),
600        Felt::new(22),
601        Felt::new(21),
602        Felt::new(8),
603        Felt::new(7),
604        Felt::new(23),
605        Felt::new(8),
606        Felt::new(26),
607        Felt::new(13),
608        Felt::new(10),
609        Felt::new(9),
610    ],
611    [
612        Felt::new(9),
613        Felt::new(7),
614        Felt::new(6),
615        Felt::new(22),
616        Felt::new(21),
617        Felt::new(8),
618        Felt::new(7),
619        Felt::new(23),
620        Felt::new(8),
621        Felt::new(26),
622        Felt::new(13),
623        Felt::new(10),
624    ],
625    [
626        Felt::new(10),
627        Felt::new(9),
628        Felt::new(7),
629        Felt::new(6),
630        Felt::new(22),
631        Felt::new(21),
632        Felt::new(8),
633        Felt::new(7),
634        Felt::new(23),
635        Felt::new(8),
636        Felt::new(26),
637        Felt::new(13),
638    ],
639    [
640        Felt::new(13),
641        Felt::new(10),
642        Felt::new(9),
643        Felt::new(7),
644        Felt::new(6),
645        Felt::new(22),
646        Felt::new(21),
647        Felt::new(8),
648        Felt::new(7),
649        Felt::new(23),
650        Felt::new(8),
651        Felt::new(26),
652    ],
653    [
654        Felt::new(26),
655        Felt::new(13),
656        Felt::new(10),
657        Felt::new(9),
658        Felt::new(7),
659        Felt::new(6),
660        Felt::new(22),
661        Felt::new(21),
662        Felt::new(8),
663        Felt::new(7),
664        Felt::new(23),
665        Felt::new(8),
666    ],
667    [
668        Felt::new(8),
669        Felt::new(26),
670        Felt::new(13),
671        Felt::new(10),
672        Felt::new(9),
673        Felt::new(7),
674        Felt::new(6),
675        Felt::new(22),
676        Felt::new(21),
677        Felt::new(8),
678        Felt::new(7),
679        Felt::new(23),
680    ],
681    [
682        Felt::new(23),
683        Felt::new(8),
684        Felt::new(26),
685        Felt::new(13),
686        Felt::new(10),
687        Felt::new(9),
688        Felt::new(7),
689        Felt::new(6),
690        Felt::new(22),
691        Felt::new(21),
692        Felt::new(8),
693        Felt::new(7),
694    ],
695];
696
697// ROUND CONSTANTS
698// ================================================================================================
699
700/// Rescue round constants;
701/// computed as in [specifications](https://github.com/ASDiscreteMathematics/rpo)
702///
703/// The constants are broken up into two arrays ARK1 and ARK2; ARK1 contains the constants for the
704/// first half of RPO round, and ARK2 contains constants for the second half of RPO round.
705const ARK1: [[Felt; STATE_WIDTH]; NUM_ROUNDS] = [
706    [
707        Felt::new(5789762306288267392),
708        Felt::new(6522564764413701783),
709        Felt::new(17809893479458208203),
710        Felt::new(107145243989736508),
711        Felt::new(6388978042437517382),
712        Felt::new(15844067734406016715),
713        Felt::new(9975000513555218239),
714        Felt::new(3344984123768313364),
715        Felt::new(9959189626657347191),
716        Felt::new(12960773468763563665),
717        Felt::new(9602914297752488475),
718        Felt::new(16657542370200465908),
719    ],
720    [
721        Felt::new(12987190162843096997),
722        Felt::new(653957632802705281),
723        Felt::new(4441654670647621225),
724        Felt::new(4038207883745915761),
725        Felt::new(5613464648874830118),
726        Felt::new(13222989726778338773),
727        Felt::new(3037761201230264149),
728        Felt::new(16683759727265180203),
729        Felt::new(8337364536491240715),
730        Felt::new(3227397518293416448),
731        Felt::new(8110510111539674682),
732        Felt::new(2872078294163232137),
733    ],
734    [
735        Felt::new(18072785500942327487),
736        Felt::new(6200974112677013481),
737        Felt::new(17682092219085884187),
738        Felt::new(10599526828986756440),
739        Felt::new(975003873302957338),
740        Felt::new(8264241093196931281),
741        Felt::new(10065763900435475170),
742        Felt::new(2181131744534710197),
743        Felt::new(6317303992309418647),
744        Felt::new(1401440938888741532),
745        Felt::new(8884468225181997494),
746        Felt::new(13066900325715521532),
747    ],
748    [
749        Felt::new(5674685213610121970),
750        Felt::new(5759084860419474071),
751        Felt::new(13943282657648897737),
752        Felt::new(1352748651966375394),
753        Felt::new(17110913224029905221),
754        Felt::new(1003883795902368422),
755        Felt::new(4141870621881018291),
756        Felt::new(8121410972417424656),
757        Felt::new(14300518605864919529),
758        Felt::new(13712227150607670181),
759        Felt::new(17021852944633065291),
760        Felt::new(6252096473787587650),
761    ],
762    [
763        Felt::new(4887609836208846458),
764        Felt::new(3027115137917284492),
765        Felt::new(9595098600469470675),
766        Felt::new(10528569829048484079),
767        Felt::new(7864689113198939815),
768        Felt::new(17533723827845969040),
769        Felt::new(5781638039037710951),
770        Felt::new(17024078752430719006),
771        Felt::new(109659393484013511),
772        Felt::new(7158933660534805869),
773        Felt::new(2955076958026921730),
774        Felt::new(7433723648458773977),
775    ],
776    [
777        Felt::new(16308865189192447297),
778        Felt::new(11977192855656444890),
779        Felt::new(12532242556065780287),
780        Felt::new(14594890931430968898),
781        Felt::new(7291784239689209784),
782        Felt::new(5514718540551361949),
783        Felt::new(10025733853830934803),
784        Felt::new(7293794580341021693),
785        Felt::new(6728552937464861756),
786        Felt::new(6332385040983343262),
787        Felt::new(13277683694236792804),
788        Felt::new(2600778905124452676),
789    ],
790    [
791        Felt::new(7123075680859040534),
792        Felt::new(1034205548717903090),
793        Felt::new(7717824418247931797),
794        Felt::new(3019070937878604058),
795        Felt::new(11403792746066867460),
796        Felt::new(10280580802233112374),
797        Felt::new(337153209462421218),
798        Felt::new(13333398568519923717),
799        Felt::new(3596153696935337464),
800        Felt::new(8104208463525993784),
801        Felt::new(14345062289456085693),
802        Felt::new(17036731477169661256),
803    ],
804];
805
806const ARK2: [[Felt; STATE_WIDTH]; NUM_ROUNDS] = [
807    [
808        Felt::new(6077062762357204287),
809        Felt::new(15277620170502011191),
810        Felt::new(5358738125714196705),
811        Felt::new(14233283787297595718),
812        Felt::new(13792579614346651365),
813        Felt::new(11614812331536767105),
814        Felt::new(14871063686742261166),
815        Felt::new(10148237148793043499),
816        Felt::new(4457428952329675767),
817        Felt::new(15590786458219172475),
818        Felt::new(10063319113072092615),
819        Felt::new(14200078843431360086),
820    ],
821    [
822        Felt::new(6202948458916099932),
823        Felt::new(17690140365333231091),
824        Felt::new(3595001575307484651),
825        Felt::new(373995945117666487),
826        Felt::new(1235734395091296013),
827        Felt::new(14172757457833931602),
828        Felt::new(707573103686350224),
829        Felt::new(15453217512188187135),
830        Felt::new(219777875004506018),
831        Felt::new(17876696346199469008),
832        Felt::new(17731621626449383378),
833        Felt::new(2897136237748376248),
834    ],
835    [
836        Felt::new(8023374565629191455),
837        Felt::new(15013690343205953430),
838        Felt::new(4485500052507912973),
839        Felt::new(12489737547229155153),
840        Felt::new(9500452585969030576),
841        Felt::new(2054001340201038870),
842        Felt::new(12420704059284934186),
843        Felt::new(355990932618543755),
844        Felt::new(9071225051243523860),
845        Felt::new(12766199826003448536),
846        Felt::new(9045979173463556963),
847        Felt::new(12934431667190679898),
848    ],
849    [
850        Felt::new(18389244934624494276),
851        Felt::new(16731736864863925227),
852        Felt::new(4440209734760478192),
853        Felt::new(17208448209698888938),
854        Felt::new(8739495587021565984),
855        Felt::new(17000774922218161967),
856        Felt::new(13533282547195532087),
857        Felt::new(525402848358706231),
858        Felt::new(16987541523062161972),
859        Felt::new(5466806524462797102),
860        Felt::new(14512769585918244983),
861        Felt::new(10973956031244051118),
862    ],
863    [
864        Felt::new(6982293561042362913),
865        Felt::new(14065426295947720331),
866        Felt::new(16451845770444974180),
867        Felt::new(7139138592091306727),
868        Felt::new(9012006439959783127),
869        Felt::new(14619614108529063361),
870        Felt::new(1394813199588124371),
871        Felt::new(4635111139507788575),
872        Felt::new(16217473952264203365),
873        Felt::new(10782018226466330683),
874        Felt::new(6844229992533662050),
875        Felt::new(7446486531695178711),
876    ],
877    [
878        Felt::new(3736792340494631448),
879        Felt::new(577852220195055341),
880        Felt::new(6689998335515779805),
881        Felt::new(13886063479078013492),
882        Felt::new(14358505101923202168),
883        Felt::new(7744142531772274164),
884        Felt::new(16135070735728404443),
885        Felt::new(12290902521256031137),
886        Felt::new(12059913662657709804),
887        Felt::new(16456018495793751911),
888        Felt::new(4571485474751953524),
889        Felt::new(17200392109565783176),
890    ],
891    [
892        Felt::new(17130398059294018733),
893        Felt::new(519782857322261988),
894        Felt::new(9625384390925085478),
895        Felt::new(1664893052631119222),
896        Felt::new(7629576092524553570),
897        Felt::new(3485239601103661425),
898        Felt::new(9755891797164033838),
899        Felt::new(15218148195153269027),
900        Felt::new(16460604813734957368),
901        Felt::new(9643968136937729763),
902        Felt::new(3611348709641382851),
903        Felt::new(18256379591337759196),
904    ],
905];