Opcodes · crypto · enabled

OP_SHA1 (0xa7)

Replaces the top item with its SHA-1 hash (20 bytes). SHA-1 is broken for collision resistance; avoid it in new contracts.

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).
Bitcoin status
Same in Bitcoin (BTC)

Example

<'abc'> OP_SHA1

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)