{"id":37324,"date":"2020-05-02T11:00:20","date_gmt":"2020-05-02T08:00:20","guid":{"rendered":"https:\/\/forklog.com\/en\/?p=37324"},"modified":"2025-08-29T15:18:30","modified_gmt":"2025-08-29T12:18:30","slug":"what-is-a-multisignature-what-is-a-ring-signature","status":"publish","type":"post","link":"https:\/\/u1f987.com\/en\/what-is-a-multisignature-what-is-a-ring-signature\/","title":{"rendered":"What is a multisignature? What is a ring signature?"},"content":{"rendered":"
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1<\/span><\/p>\n

What is a multisignature?<\/strong><\/p>\n

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A multisignature (multisignature or multisig) is a technique for authorising transactions with multiple private keys, raising security and privacy during the approval of outgoing transfers.<\/p>\n

A multisignature is a form of threshold signature<\/a>, implemented as a verification of conditions expressed in the cryptocurrency\u2019s base scripting language.<\/p>\n<\/div>\n<\/div>\n

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2<\/span><\/p>\n

How and when did multisignatures emerge? <\/strong><\/p>\n

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Although the technology is widespread in cryptocurrencies, its fundamentals long predate bitcoin.<\/p>\n

For centuries a multisig-like principle was used to protect monastery vaults or crypts that held holy relics. An abbot distributed parts of the keys among monks. No monk could access the relics alone and steal them.<\/p>\n

Multisignature support was first implemented for Bitcoin addresses in 2012. The first wallet with multisig functionality was created<\/a> in 2013. Today there are more than a dozen.<\/p>\n<\/div>\n<\/div>\n

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3<\/span><\/p>\n

How do multisignatures work? <\/strong><\/p>\n

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Access to funds in a multisig wallet is possible only when two or more signatures are presented concurrently.<\/p>\n

A simple analogy is a safe-deposit box with two locks and two keys. Maria holds one key, Juan the other. They can open the box only if they present both keys at the same time. Neither can open it unilaterally without the other\u2019s consent.<\/p>\n

Thus, multisig wallets add an extra layer of security. The approach helps users avoid problems typical of single-key wallets, which represent a single point of failure and are vulnerable to cybercriminals\u2019 constantly evolving phishing tactics.<\/p>\n

Because spending requires more than one signature, multisig also suits businesses and corporations that want to keep funds in shared wallets.<\/p>\n<\/div>\n<\/div>\n

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4<\/span><\/p>\n

What kinds of multisignature setups exist? <\/strong><\/p>\n

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1-of-2: a joint account of two business partners \u2014 either party\u2019s signature suffices to spend funds.<\/p>\n

2-of-2: a joint savings account of two business partners \u2014 both signatures are required, preventing one owner from spending without the other\u2019s approval.<\/p>\n

2-of-2: a wallet with two-factor authentication \u2014 one key is stored on a computer, the other on a smartphone. Funds cannot be spent without signatures from both devices.<\/p>\n

3-of-5: a low-trust donations address \u2014 each of five trusted project participants holds a private key. Any three can spend funds, while anyone can donate to the project\u2019s address. This arrangement reduces the risk of embezzlement, hacks, malware and loss caused by a participant losing interest. The blockchain records which private key was used for the final signature, improving accounting.<\/p>\n

2-of-3: a buyer\u2013seller escrow without trust \u2014 the buyer sends funds to a 2-of-3 address, the seller acts as the third arbiter.<\/p>\n

If the transaction succeeds, buyer and seller both sign, releasing funds to the seller. If it fails, they can co-sign a refund to the buyer.<\/p>\n

If they cannot agree, both turn to the third party, which acts as arbiter and provides the second signature to the side it deems deserving. The arbiter cannot steal the funds because it holds only one key.<\/p>\n

2-of-3: a council of three custodians holds a company\u2019s or organisation\u2019s funds \u2014 spending requires consent from any two of the three. Larger organisations can use bigger multisig setups \u2014 3-of-5, 5-of-9, and so on.<\/p>\n

2-of-3: a hot wallet for businesses. A bitcoin exchange keeps one private key online and another as a paper backup. A separate cybersecurity company holds the third key online and signs only after checking several factors (black\/white lists, withdrawal limits over a period, two-factor authentication, regulatory compliance, etc.). If the exchange\u2019s hot wallet is hacked, bitcoins cannot be stolen. If the security firm ceases operations, the exchange can access funds via the paper backup.<\/p>\n

2-of-3: a decentralised cold-storage vault \u2014 one key is kept by the user in a home safe, the second in a bank deposit box, and a copy of the third key is held by a close friend or relative at their office. The home safe is protected from burglars because spending requires a visit to the friend, the bank or the office.<\/p>\n

2-of-2: smart contracts \u2014 TumbleBit, Coinswap<\/a>, Lightning Network.<\/p>\n

1 or 3-of-4: distributed recovery \u2014 the primary user can spend at will, but if they lose their private keys, access can be restored with three of four other trusted friends\/organisations. One key is stored in a bank deposit box, the other three with friends. In the event of the owner\u2019s death, the vault with funds can, under a will, be transferred to a trusted friend or someone who can obtain assistance from the trusted friends.<\/p>\n<\/div>\n<\/div>\n

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5<\/span><\/p>\n

What are ring signatures?<\/strong><\/p>\n

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A ring signature is a type of cryptographic digital signature that can be produced by any member of a group of users, each of whom holds a key.<\/p>\n

One security property is that it is computationally infeasible to determine which member\u2019s key was used to sign. Ring signatures resemble group signatures<\/a> but differ in two ways: an individual signature cannot be deanonymised, and any members of any user group can act as signers without extra setup.<\/p>\n

The term \u201cring signature\u201d comes from the ring-like structure of the signature-generation algorithm.<\/p>\n<\/div>\n<\/div>\n

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6<\/span><\/p>\n

Who invented ring signatures, and when? <\/strong><\/p>\n

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Ring signatures were invented by cryptographers Ron Rivest<\/a>, Adi Shamir and Yael Tauman Kalai and were presented<\/a> at the ASIACRYPT international conference in 2001.<\/p>\n

The original concept envisaged ring signatures as a way to protect against leaks of classified information, notably from government offices. The initial model was later refined.<\/p>\n

In 2006 Eiichiro Fujisaki and Kotaro Suzuki proposed Traceable Ring Signatures<\/a>, addressing a vulnerability in ring signatures (the risk of manipulation by malicious or irresponsible signers). An optimised version of this variant is used in CryptoNote coins today, providing sender untraceability in P2P transactions by hiding the source of inputs.<\/p>\n

In 2015 Monero Research Labs advanced the idea of ring confidential transactions (Ring Confidential Transactions<\/a>), which Bitcoin Core developer Gregory Maxwell presented and implemented. Extending the anonymisation of basic ring signatures, ring confidential transactions hide not only the sender\u2019s identity but also the amounts exchanged between sender and recipient.<\/p>\n<\/div>\n<\/div>\n

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7<\/span><\/p>\n

How do ring signatures work? <\/strong><\/p>\n

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Ring signatures take the idea of group signatures a step further, offering greater privacy. In P2P transaction formats used by cryptocurrencies such as CryptoNote<\/a>, ring signatures protect the sender by obscuring the receiving side of the transaction so that it is computationally infeasible to determine who signed it.<\/p>\n

Ring signatures are more sophisticated than typical digital signatures such as ECDSA or Schnorr signatures.<\/p>\n