When it comes to verifying the authenticity or truthfulness of something, the phrase "attested to" is often used. However, there are several other synonyms that can be used to convey the same meaning. Such synonyms include validated, substantiated, confirmed, endorsed, vouched for, certified, affirmed, proved, and supported. All of these words carry the connotation of providing evidence or proof to support a claim or statement. Whether it's a legal document, scientific research, or personal testimony, using any of these synonyms will effectively communicate that the information has been verified and can be trusted.