Specifies a list of cipher suites that are allowed by connections using TLS version 1.3.
At a glance
| Property | Value |
|---|---|
| Parameter | ssl_tls13_ciphers |
| Category | Connections and Authentication |
| Default | (see documentation) |
| Value type | string |
| Change scope | Reload (postgresql.conf, SIGHUP) |
| Available in | PostgreSQL 18, 19 (added in 18) |
What it does
Specifies a list of cipher suites that are allowed by connections using TLS version 1.3. Multiple cipher suites can be specified by using a colon-separated list. If left blank, the default set of cipher suites in OpenSSL will be used.
This parameter can only be set in the postgresql.conf file or on the server command line.
(Description quoted from the official PostgreSQL documentation.)
How to apply a change
Set it in postgresql.conf (or with ALTER SYSTEM) and reload with SELECT pg_reload_conf(); or pg_ctl reload — no restart needed.
Inspect the current value and source with SHOW ssl_tls13_ciphers; or SELECT name, setting, unit, context, source FROM pg_settings WHERE name = 'ssl_tls13_ciphers';.
Tuning guidance
This is a connectivity or security setting, not a performance knob. Choose the value from your security and network requirements (TLS files, ciphers, keepalives, authentication behaviour) rather than for throughput, and verify it against your organization’s policy. Test changes in staging, because a wrong value here can lock clients out.