Authentication is a process by which governments confirm the authenticity of the documents included in your dossier. This is a very important step in the International Adoption process, and must therefore be process precisely. The following is an example of how to go about with it:

For your Financial Statement, you and your spouse must sign the said document in the presence of an authorized state notary.
Your notarized Financial Statement will be sent to the State Authentication office for them to verify the authority of the state notary who notarized your document. After they have verified the state notary, The Authentication Office will then affix their Seal of Approval with the necessary official documents. This will then be attached to your notarized Financial Statement as proof of their approval.
The set of documents will then be sent to the United States Department of Authentications in Washington, D.C. This Department will examine the letter and seal of the State Authorization Office. They will then affix their own seal and letter confirming that all the documents are authentic.
The new set of documents will be sent to the foreign Embassy. After confirming that the documents passed through the U.S. Department of Authentications, they will affix their seal and stamp of approval.
After all these, the documents are ready to be presented to the government of your child’s native country.
If you were born in a state other than where you reside right now, you have to ask for certified copies of your Birth Certificate from the state of your birth. The copies also need to be authenticated by the Authentication Office of your state of birth. After which, the documents will follow the same procedures as described above.