How the letters are kept
We do not know how God reads. So we publish the letters in several forms, keep them open to anyone, and mean to copy them to more places than one.
Formats
Places
Answer words
Every sealed letter carries twelve random words inside it that no one has seen. Only their fingerprint is published. If anyone ever says them on the answer page, the letter is marked as opened, for everyone to see. It is how a writer would know, and how everyone would know if the seal were ever broken.
The seal page
You don't have to trust this site to seal a letter. The seal page is a single file of 156 KB that contains everything it does, published on IPFS. On IPFS a file's address is the fingerprint of its content: if one character changed, the address would change. The page can send a letter only to this site, and only once it is sealed.
489656129a87523d587ad95217d69d6d9094795b385b741063439f2748e97078Checking a letter
Every sealed letter has a seal fingerprint, shown on its receipt. On the verify page, your own browser recomputes it from the archive and shows the letter's place in the Book of God, the yearly volume timestamped on Bitcoin.
Withdrawing a letter
Every receipt carries a code. With it you can delete your letter at any time: it is removed from the site and left out of every copy made afterwards. Open letters wait a day before they are published, so there is time to change your mind.
About sealed letters
A sealed letter is encrypted in your own browser with AES-256, using a key made for that letter alone. The key is never saved and never sent. It is padded first, so its length shows only roughly. What reaches us, and what we publish, is only the ciphertext. We cannot read it, and neither can anyone who copies the archive. It is delivered all the same. The day it was sent can still be seen.