uuid_generate_v1mc() from the uuid-ossp extension uses a randomly generated mac, so no leakage and entropy is increased. The timestamp portion is a feature IMO,

uuid_generate_v1mc() from the uuid-ossp extension uses a randomly generated mac, so no leakage and entropy is increased. The timestamp portion is a feature IMO, not a bug. It prevents index and page thrashing in Postgres. (Also doubles as a "created_at" field, but that's getting "tricky". https://www.postgresql.org/docs/current/uuid-ossp.html#UUID-OSSP-FUNCTIONS-SECT https://www.postgresql.org/docs/current/uuid-ossp.html#UUID-... Obviously clients should use this variant as well if you're using v1.