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Crypto-Judaism: Is Bitcoin Money?

Adapted from the writings of Dayan Yitzhak Grossman

August 19, 2021


Several months ago, Peter Kacherginsky and Rebecca Rose “got married on the blockchain”:

In addition to a traditional Jewish ceremony, we wanted to solidify our vows in a more personal way. Since we both work at @Coinbase, @_iphelix (Kacherginsky) wrote an @Ethereum smart contract for our marriage that issued digital artwork as tokens (#NFTs) to our cryptocurrency wallets. The name of the token is Tabaat, the Hebrew word for ring….

As part of the ceremony we exchanged #NFTs, much like rings, by sending them to each other from our #cryptocurrency wallets….

In this article, we explore the halachic validity of kidushin performed via the transfer of cryptocurrency or non-fungible tokens (NFTs).[1]

Paper money

Two centuries ago, poskim debated the halachic status of a then-novel form of money: banknotes—negotiable promissory notes, issued by a bank or other licensed authority, payable to the bearer on demand—the precursors of modern paper money. The primary question was whether they were considered money (ma’os or matbeia), have inherent value (gufo mamon), and are the equivalent of the metal coins which had been traditionally used as money. Alternatively, perhaps they are only considered notes (shtaros), which are not gufo mamon. Most poskim considered them ma’os and gufo mamon, albeit for a variety of different reasons:

  • R’ Meshulam Igra argues that the defining characteristic of shtaros is that even if they are destroyed, the value they represent is still accessible if the underlying facts can be established. This is not the case with banknotes, where the issuer is exempt from payment if the notes have been destroyed, even if witnesses testify to the destruction.[2] [3]
  • R’ Meshulam Igra’s successor as the rav and rosh yeshiva of Pressburg, the Chasam Sofer, also maintains that banknotes are considered money, but on different grounds: Money is whatever the government decrees to be legal tender, and there is no difference between paper and metal. If a certain medium of exchange is mandated to be accepted by everyone as payment, and refusal to do so is a capital offense (!), that medium is considered money and has the status of gufo mamon.[4]
  • R’ Moshe Teitelbaum (of Újhely, a contemporary of the Chasam Sofer) maintains that in our context, the status of gufo mamon hinges on something being a universal medium of exchange: It is possible to buy anything with it. Since banknotes have this property, they are gufo mamon and are not shtaros.[5]

While there is a minority view that banknotes are indeed shtaros,[6] the halachic consensus is that they are not.[7]


Turning to cryptocurrency, the first question to consider is whether it is even recognized in halacha as property at all, since it is intangible and consists of nothing more than mere information! R’ Asher Weiss raises this possibility, but summarily rejects it, because cryptocurrency’s reality is obvious given the amount of money invested in it and the seriousness with which it is taken. In light of the latter two of the aforementioned defining characteristics of money, however, he concludes that since cryptocurrency is not deemed legal tender by governments[8] and is only very rarely accepted as payment, it does not currently have the status of money, and it is thus a mere asset or commodity. If one stole it (if that were possible), he would be liable for the theft, but it does not have the status of money in contexts such as kinyanim and ribbis (with regard to the prohibition of se’ah bes’ah, which generally forbids loans of assets other than currency—where the original assets are spent or consumed, and equivalent ones are later repaid—unless denominated in currency).[9]

R’ Shlomo Ishon (the head of Mechon Keter, an Israeli institute devoted to developing halachic resolutions to modern economic questions) reaches a similar conclusion: “in the current situation, [cryptocurrency] would be not be considered money, but rather merchandise or a shtar chov.”[10] (He does not explain the logic of considering it the latter; perhaps the resemblance to shtaros is in the fact that the digital keys—mere numbers—are worthless in and of themselves, and only obtain their value within the consensus of a given cryptocurrency framework.) R’ Shlomo Aviner also adopts a similar position, that cryptocurrency could in principle be considered money were it to become widely used as such, but this is not currently the case, so it is currently considered an ordinary asset, and it may not be loaned.[11]


According to these contemporary poskim, it would seem possible at least in principle to perform kidushin with cryptocurrency, since currency is not required (and indeed, is not normally used) for kidushin.[12]

NFTs, however, raise additional questions of valuation: kidushin performed with “an item in whose valuation people are not proficient, and they sometimes err greatly” in assessing its value are problematic,[13] and there are surely few things to which this description applies as well as it does to NFTs. A more detailed discussion of this issue, however, is beyond the scope of this article.


[1]We will not deal here with the question of the validity of double ring ceremonies.

[2]Shu”t R’ Meshulam Igra C.M. siman 16, and cf. Shu”t Maharsham cheilek 2 siman 100.

[3]Note that this is not the case with modern paper money, at least U.S. currency; see Redeem Mutilated Currency. U.S. Bureau of Engraving and Printing.; Turning damaged dollars into crisp cash. USA Today.; Susan Tompor. Dog chewed up your cash? What to do. USA Today.

[4]Shu”t Chasam Sofer Y.D. siman 134 from s.v. Vesu kvar he’elah and C.M. siman 187 from s.v. Venidon habanki.

[5]Shu”t Heishiv Moshe (Y.D.) siman 55.

[6]See Shu”t Bais Shlomo C.M. siman 34; Chochmas Shlomo beginning of siman 292 (and cf. end of siman 74) and Shu”t Ha’elef Lecha Shlomo C.M. siman 6. Cf. Shu”t Machanei Chaim cheilek 2 E.H. siman 26.

[7]Minchas Pitim C.M. end of siman 303; Shu”t Zekan Aharon cheilek 1 (C.M.) siman 98 end of s.v. Ulefi ha’amur; Aruch Hashulchan C.M. 68:9 (with regard to negotiable banknotes usable as currency).

[8]El Salvador recently became the first country in the world to make Bitcoin legal tender: see Bitcoin: El Salvador makes cryptocurrency legal tender. BBC News.

[9]HaBitcoin Bahalacha (audio).

[10]Matbeia Virtuali (Bitcoin)–Ha’im Nechshav Matbeia Al Pi Hahalacha (also available here).

[11]Bitcoin–Zeh Kessef? Kipa.—%D7%96%D7%94-%D7%9B%D7%A1%D7%A3/.

Cf. R’ Shlomo Gintzler. Shekel Kessef: Kessef Digitali Bahalacha, Vehagdaraso Shel Kessef HaTorah. Yeshurun 33 (Elul 5775) pp. 606-26.

R’ Avraham Meir Rabinowitz. Crypto, Bitcoin, Blockchain BaHalacha: Mah Hama’amad Hahilchasi Shel Matbeios Virtuali’im?

R’ Yehudah Odesser. Keniyah Umechirah Im Bitcoin.

[12]Performing kidushin with a debt against a third party is discussed in Shulchan Aruch E.H. 28:13, but the issues discussed there would not seem to apply to cryptocurrency even if it were to be considered shtaros.

The Chasam Sofer (Y.D. 134) writes that according to his legal tender criterion for something to have the status of money, “there is no doubt that these banknotes are fully considered to be money, even to be mekadeish a woman with them, and they are perfectly like [the money Avraham paid to] Efron.” The Chasam Sofer is referring to the derivation of kidushei kessef from the purchase of Efron’s field (Kidushin 4b), but the implication of his comments that according to the opposing view that banknotes are not considered money, they could not be used for kidushin, is puzzling, since as noted, all assets, even (at least in principle) shtaros, can be used for kidushin.

[13]See Shulchan Aruch E.H. 31:2.

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