Enigma Technologies Solutions · Secret sharing for Sanctum
\nsplitcombine
\nSplit a secret into shares. Any k of them rebuild it. Fewer than the needed number reveal nothing about the secret's content; the size bucket and the needed number are visible in every share. Everything runs in this window. Nothing is stored or sent.
\n01 · Split
\nTurn one secret into shares
\nEnter a secret, choose how many shares to make and how many are needed to rebuild it, then split.
\n\nSecret
\nHidden while you type. Line breaks are kept.
\n \nGenerate makes a random secret from 28 easy to read letters and digits. At 32 characters that is 153.8 bits.
\nCheck value (SHA-256)
\nShow the secret to see this value.
\nAnyone who sees this value can test guesses against it. Do not store it next to the shares.
\nShares
\n\n \n
Letters, digits, dot, underscore, hyphen; up to 32. Helps you tell sets apart. It is not secret and not checked.
\nOptions
\n \n \nRounds the hidden data up to a multiple of this size, so a share does not show the exact length. It hides the length inside that range, not the fact that a secret exists.
\nShares
\n \nInputs changed. Split again.
\n \n02 · Combine
\nRebuild a secret from shares
\nPaste at least as many shares as were needed. Extra shares are fine.
\n\nPlain shares do not record this. If you fill it in, extra shares are checked against each other.
\nSecret
\n \n \nCheck value (SHA-256)
\nShow the secret to see this value.
\nAnyone who sees this value can test guesses against it. Do not store it next to the shares.
\nHow this works and what it does not protect
\n- \n
- The scheme. Shamir's secret sharing works on each byte of the secret in a field of 256 values. Any k shares rebuild the secret. Fewer than k reveal nothing about it, however much computing power they have, as long as the random numbers were good. \n
- Randomness. Random numbers come from this window's secure random source. If it is missing, the tool stops instead of using something weaker. \n
- Two formats. A Sanctum share adds the number of shares needed, a set id, a checksum on the share and a check value hidden inside the secret. The tool can then tell you when a share is mistyped, missing or from another set. These checks are not secret, so they do not prove the secret is the original. A plain share has none of this and matches ssss-made-easy and the shamir-secret-sharing package. \n
- Not the ssss command line. These shares do not work with the ssss-split and ssss-combine programs. \n
- What it covers. It protects against lost and mistyped shares. It does not protect against a dishonest share holder, malware, screen capture or another program reading the clipboard. Someone holding enough other shares can invent a share that rebuilds a secret of their choice, so the checks catch accidents, not cheating. \n
- Length. Every share is about as long as the secret. The length option pads the hidden data so the exact size is not visible. \n
- Cleanup. Nothing is stored. Clear empties the fields and the bytes this page holds, where it can. The idle timer only hides the secret again after 60 seconds without typing. Browsers may keep copies of text in memory, so treat this as best effort. \n