eCash / Chaumian eCash
Cryptography● Common

A digital cash system invented by David Chaum using blind signatures to create untraceable tokens. The mint signs tokens without seeing their content; tokens can be verified as valid without linking to issuance. Used in Fedimint and Cashu.

Technical Notes

User creates token T, blinds as T' = T·r^e (RSA) or T' = T + r·G (EC), mint signs blind token, user unblinds signature. Mint verifies signature on redemption but cannot link to issuance. Double-spend prevention requires mint database.

Metadata

Visibility: Public
Created:1/3/2026by System

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