Studio C6's seal
Every document signed through Studio C6 is sealed with this certificate once everyone has signed. Any change to a sealed PDF breaks the seal.
SHA-256 fingerprint:
56:FF:69:D3:CF:79:F4:77:26:04:EC:F2:9F:39:92:9F:3C:17:DE:74:4F:ED:FB:F0:C6:1F:C4:F8:DF:87:3F:C2
To check a document: open it in Adobe Acrobat or another PDF reader, open its signature panel, and look at the seal's certificate details. Its SHA-256 fingerprint must be the one above. Acrobat says the signer's identity is unknown because Studio C6 issues this certificate itself; the fingerprint is how you know it's ours.