LAWS.xts_blocks_round_trip: law of bend-osdev-cipher-modes@0.1.0.0
Import: import bend-osdev-cipher-modes@0.1.0.0/LAWS.bend as LAWS
Lines 44-54 of bend-osdev-cipher-modes@0.1.0.0/LAWS.bend: https://jend.leeeet.dev/read.txt?path=bend-osdev-cipher-modes@0.1.0.0/LAWS.bend&start_line=44&end_line=54

import Base
import bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend as M
import bend-osdev-cipher-modes@0.1.0.0/xts.bend as T

# XTS on blocks: decryption undoes encryption, for every data key and every
# starting tweak (T_0 = Xts.tweak(k2, i), so every k2 and i are covered)
law xts_blocks_round_trip:
  for ~K: Data
  for ~enc: K -> M.CmBlock -> M.CmBlock
  for ~dec: K -> M.CmBlock -> M.CmBlock
  for ~inv: @k: K -> @b: M.CmBlock -> {dec(k, enc(k, b)) == b : M.CmBlock}
  for +k1: K
  for t: M.CmBlock
  for bs: List<&2, M.CmBlock>
  {T.Xts.decrypt_blocks(~K, ~dec, k1, t, T.Xts.encrypt_blocks(~K, ~enc, k1, t, bs)) == bs : List<&2, M.CmBlock>}

Uses (9):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/PROOF.bend&name=tr.xts_dec_eq
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/PROOF.bend&name=tr.xts_enc_eq
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/PROOF.bend&name=xtsp.go
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend&name=CmBlock
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/xts.bend&name=Xts.decrypt_blocks
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/xts.bend&name=Xts.encrypt_blocks
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/xts.bend&name=xts.dec.fast
  https://jend.leeeet.dev/definition.txt?path=bend-osdev-cipher-modes@0.1.0.0/xts.bend&name=xts.enc