The current bom 1.6 schema does not define a `properties` field for arbitrary name-value pairs within [cryptoProperties](https://github.com/CycloneDX/specification/blob/master/schema/bom-1.6.schema.json#L5044). For example, it appears not possible to specify custom name-value pairs under [certificateProperties](https://github.com/CycloneDX/specification/blob/master/schema/bom-1.6.schema.json#L5325).