Crypto Dictionary
Soft Fork
Definition
A change to the software protocol where only previously valid transaction blocks are made invalid.
Deep Dive
A soft fork is a backward-compatible upgrade to a blockchain's protocol. This means that nodes running the *old* software version will still recognize blocks produced by nodes running the *new* software as valid, as long as the new rules are a *subset* of the old rules. Effectively, a soft fork tightens the rules, making some previously valid transactions or blocks invalid under the new protocol, but not invalidating blocks made under the old, broader rules.
Examples & Use Cases
- 1The Segregated Witness (SegWit) upgrade on Bitcoin and Litecoin, which allowed for more transactions per block by restructuring transaction data, while still being compatible with older nodes.
- 2The Taproot upgrade on Bitcoin, which enhanced privacy and efficiency for complex transactions through a soft fork.
- 3Many minor security patches or feature improvements on existing blockchains that only invalidate certain edge cases of transactions.
Related Terms
Hard ForkBackward CompatibleProtocol Upgrade