Opcodes · crypto · enabled

OP_HASH256 (0xaa)

Replaces the top item with its double SHA-256 hash (32 bytes). Used in P2SH32 (2023) and to compute transaction IDs.

Verified
Stack in → out
x → hash(x)
Since
Original Bitcoin script
Cost
Base instruction cost 100 plus result length, plus 192 per hash digest iteration under relay policy (64 under consensus); digest iterations also count toward the per-input hashing limit (2025 VM limits). The two-round hash adds one extra digest iteration.
Bitcoin status
Same in Bitcoin (BTC)

Example

<'abc'> OP_HASH256

Step through it opcode by opcode in Bitauth IDE, the in-browser BCH VM debugger.

Sources

  1. Libauth BCH_2023_05 opcodes (bch-2023-opcodes.ts)
  2. CHIP-2021-05 VM Limits: Targeted Virtual Machine Limits
  3. BCHN VM limits (vm_limits.h)