3 ms·
It’s a checksum; by decomposing every transaction into a double of (credit A, debit B) that must sum to zero, you catch random arithmetic errors. You can think
by theptip 3y ago
It’s a checksum; by decomposing every transaction into a double of (credit A, debit B) that must sum to zero, you catch random arithmetic errors.
You can think of it as “conservation of value”, so you can’t just create money out of thin air in your payment service (credit), without tying it to some account with a corresponding debit.
This originally was intended to protect against typos; eg write a 10 instead of 100, at the end of the day your ledger needs to balance. In software typos are less likely bit it still provides auditability to prevent a large class of bugs from wiping you out.
- dragonwriter 3y ago> This originally was intended to protect against typos; Double entry bookkeeping is much older than typing, but, yes, its a check against incorrect entries.
- ectopasm83 3y agoBabylonian dogs walking on your clay tablet.
- jimbokun 3y agoCats, more likely.
- jacques_chester 3y agoSpeaking of history, I learned that the word "control" comes from contra rotulus -- roughly "checking against the wheel", which was apparently from an early medieval device for keeping tallies. The second meaning of "domination" came later.