Civil Law and Crypto-Asset Custody Disputes in Europe

1. Introduction

Crypto-asset custody disputes arise when a customer entrusts cryptocurrency or other crypto-assets to an exchange, wallet provider, broker, custodian, or crypto-asset service provider and subsequently alleges:

unauthorised transfer;

hacking;

loss of private keys;

failure to safeguard assets;

wrongful freezing of an account;

inability to withdraw assets;

insolvency of the custodian;

misappropriation by an employee or third party;

incorrect execution of a transfer;

failure to comply with contractual security procedures;

inadequate cybersecurity;

failure to identify fraudulent transactions;

disputes over ownership or beneficial entitlement.

European law is developing rapidly in this field. The legal analysis combines traditional civil-law concepts of ownership, custody, contract, restitution and tort with the newer regulatory framework for crypto-assets.

A particularly useful recent French appellate decision concerns Paymium and its Blockchain.io platform, while the English cases provide important comparative authorities on crypto-assets as property, tracing and exchange/custodian liability. Because direct European civil-law case law remains comparatively limited, it is important to distinguish direct civil-law authorities from comparative common-law authorities.

2. Meaning of Crypto-Asset Custody

Custody generally means that a service provider holds or controls crypto-assets, or the cryptographic means of accessing them, on behalf of a customer.

Under the EU's Markets in Crypto-Assets Regulation (MiCA), “custody and administration of crypto-assets on behalf of clients” is expressly recognised as a crypto-asset service.

The French courts have similarly described crypto-asset custody as a service involving the holding, storing and transferring of digital assets or access to them, including through private cryptographic keys. (Cour de Cassation)

This creates a fundamental civil-law question:

What exactly has the customer entrusted to the custodian?

Possible answers include:

ownership of particular crypto-assets;

contractual rights against the platform;

control over wallet addresses;

private keys;

a contractual claim for restitution;

a combination of proprietary and contractual rights.

3. Principal Legal Issues

A typical custody dispute may involve the following sequence:

Customer → Custodian → Wallet/account → Crypto-assets → Security system → Transfer instruction

If the crypto-assets disappear, the court must determine:

First

Who owned the crypto-assets?

Second

What contractual service did the platform provide?

Third

Was the platform a custodian, intermediary, exchange, agent or merely software provider?

Fourth

Was the transfer authorised?

Fifth

Did the platform comply with its contractual security obligations?

Sixth

Was the loss caused by the platform, the customer or a third-party hacker?

Seventh

Can the claimant trace the crypto-assets?

Eighth

What remedies are available?

4. MiCA and Custody

The EU MiCA Regulation (EU) 2023/1114 is now a major part of the European regulatory framework.

Crypto-asset services include:

custody and administration;

operation of trading platforms;

exchange of crypto-assets for funds;

exchange of crypto-assets for other crypto-assets;

execution of orders;

placement;

reception and transmission of orders;

advice;

portfolio management;

transfer services.

A French court in 2026 expressly relied upon MiCA's definition of crypto-assets and its classification of custody as a regulated crypto-asset service. (Cour de Cassation)

However, regulatory authorisation does not automatically determine private-law liability.

A claimant still needs to establish:

contract + breach/fault + causation + loss, or another applicable civil cause of action.

5. Case Law

Case 1 — H v Paymium / Blockchain.io, Cour d'appel de Versailles, RG No. 24/05267

Importance

This is one of the most useful recent continental European civil-law authorities directly concerning crypto-asset custody.

The claimant alleged that crypto-assets had been stolen after a third party gained access to his systems and used the Blockchain.io platform.

He argued that Paymium should be treated as a custodian/depositary and should have had stronger security mechanisms, including mandatory two-factor authentication.

The claimant also alleged failures concerning:

custody;

cybersecurity;

vigilance;

unauthorised transfers;

personal-data security.

The court examined the contractual relationship and rejected the argument that the arrangement could simply be characterised as an ordinary civil-law deposit under Articles 1915 and following of the French Civil Code. (Cour de Cassation)

Important finding

The court nevertheless emphasised the contractual obligations governing the crypto platform.

Paymium had a system for safeguarding crypto-assets recorded in customer accounts and had contractual procedures concerning the execution and security of orders.

The claimant had chosen not to use the available two-factor authentication.

The court therefore found no demonstrated negligence by Paymium in the circumstances, particularly because the disputed transfers appeared regular under the contractual security procedures and the immediate security failure was associated with the claimant's own compromised equipment/email environment. (Cour de Cassation)

Principle

A crypto-custody arrangement is not automatically an ordinary Civil Code deposit; contractual allocation of security responsibilities is crucial.

This case is especially important for European civil-law analysis.

6. Case 2 — I v Bitstamp Europe, Cour d'appel de Grenoble, RG No. 24/02105

This case involved a customer of Bitstamp Europe.

The customer had held an account since 2017 and alleged that hackers carried out transfers from the account in November 2021.

The disputed transfers were approximately €27,950.

The customer sought:

restitution;

compensation for lost crypto-assets;

damages;

compensation for a claimed lost opportunity to realise a higher cryptocurrency value.

The case involved French Civil Code provisions concerning:

contractual force;

good faith;

contractual liability;

restitution;

deposit;

custody.

The court also considered the French regulatory framework for digital-asset service providers and the fact that Bitstamp was registered with the AMF only in February 2023, although the contractual relationship and disputed transactions predated that registration. (Cour de Cassation)

Principle

The case demonstrates that a crypto-custody dispute can involve both contractual civil liability and regulatory-status questions.

It also illustrates the difficulty of calculating damages where cryptocurrency prices fluctuate dramatically.

A claimant may assert:

“I lost the crypto-assets.”

But that does not automatically establish:

“I am entitled to the highest historical market value of those assets.”

Causation, valuation date, mitigation and proof of lost opportunity remain relevant.

7. Case 3 — AA v Persons Unknown, [2019] EWHC 3556 (Comm)

Court

High Court of England and Wales, Commercial Court.

Importance

This is a comparative common-law authority, not a civil-law case.

It is nevertheless extremely influential in European cryptoasset litigation.

The case arose after hackers demanded Bitcoin following a malware attack.

The insurer paid the ransom in Bitcoin and subsequently traced the cryptocurrency.

The court had to decide whether Bitcoin could constitute property capable of being protected through a proprietary injunction.

Holding

The court concluded that crypto-assets such as Bitcoin could constitute property for the purposes of proprietary relief.

The court considered the traditional categories of choses in possession and choses in action but concluded that crypto-assets should not be excluded merely because they do not fit neatly into those traditional categories.

Bitcoin satisfied the relevant characteristics of property and could therefore be protected through a proprietary injunction. (Courts and Tribunals Judiciary)

Principle

Crypto-assets can be treated as property capable of proprietary remedies.

European relevance

This reasoning has become highly influential in cross-border disputes involving:

ownership;

tracing;

freezing orders;

stolen cryptocurrency;

insolvency;

custody.

8. Case 4 — D'Aloia v Persons Unknown, [2022] EWHC 1723 (Ch)

Importance

This was another English High Court crypto-fraud case.

Mr D'Aloia alleged that approximately:

2.1 million USDT, and

230,000 USDC

had been fraudulently obtained from him.

The assets had moved from his Coinbase and Crypto.com wallets to wallets controlled by persons unknown. (Bailii)

The court dealt with:

interim injunctions;

disclosure;

identification of defendants;

cryptocurrency tracing;

exchange involvement;

proprietary remedies.

Principle

Crypto-asset litigation can justify urgent proprietary and disclosure relief where there is a real risk that digital assets will be moved rapidly between wallets.

The blockchain can provide a transactional trail, but identifying the legal owner or recipient behind a wallet may still require court-ordered disclosure.

9. Case 5 — D'Aloia v Persons Unknown, [2024] EWHC 2342 (Ch)

This is a later stage of the same dispute.

The claimant alleged that he had been the victim of a cryptocurrency scam involving approximately £2.5 million of cryptocurrency, which was transferred through multiple wallets and eventually reached accounts associated with crypto exchanges. (vLex)

The court considered:

crypto-assets as property;

following;

tracing;

mixed wallets;

constructive trusts;

unjust enrichment;

change of position;

ministerial receipt;

bona fide purchaser principles.

Important principle

The court held that USDT is capable of constituting property.

It also distinguished:

Following

Identifying the same asset as it moves from one location/person to another.

Tracing

Identifying a substitute asset or value through which the original property has been transformed.

The claim ultimately failed against Bitkub because the claimant could not prove, on the balance of probabilities, that his USDT had reached the relevant wallet. (ZoomLaw)

Principle

Blockchain tracing is technically possible, but legal tracing still requires sufficient evidential proof connecting the claimant's assets with the defendant's assets.

10. Case 6 — Fetch.AI Ltd v Persons Unknown, [2021] EWHC 2254 (Comm)

The claim involved cryptocurrency accounts maintained with Binance.

Unknown persons allegedly obtained access to the accounts and manipulated cryptocurrency trades by selling assets at substantial undervaluations.

The resulting loss exceeded US$2.6 million. (Bailii)

The case demonstrates how crypto custody litigation can involve:

hacking;

unauthorised account access;

manipulation of trading instructions;

transfers to third-party accounts;

proprietary claims;

freezing orders;

exchange disclosure.

Principle

An exchange account can become the subject of urgent civil remedies when unauthorised persons manipulate crypto-assets held through the platform.

11. Case 7 — Vorotyntseva v Money-4 Ltd t/a Nebeus.com, [2018] EWHC 2598 (Ch)

This is another English comparative authority.

The claimant sought a worldwide freezing order concerning substantial quantities of Bitcoin and Ethereum.

The case is significant because the court treated cryptocurrency holdings as sufficiently connected with proprietary interests to justify protective relief.

It is particularly relevant to:

freezing orders;

preservation of crypto-assets;

risk of dissipation;

proprietary remedies.

The case was subsequently referred to in AA v Persons Unknown when considering the proprietary character of cryptocurrency. (Bailii)

Principle

Crypto-assets may justify urgent protective orders because their digital nature makes rapid transfer and dissipation possible.

12. Case 8 — M v Bitstamp / crypto-exchange custody disputes

Recent French litigation demonstrates that the courts are increasingly required to determine whether an exchange relationship constitutes:

deposit;

custody;

agency;

exchange;

contractual account;

sui generis digital-asset service.

The French courts have resisted simply importing traditional bank-deposit concepts into every crypto relationship.

Instead, the court examines:

the actual contract;

the platform's terms;

who controls the private keys;

who may initiate transfers;

the platform's security obligations;

the customer's own security obligations.

This functional approach is particularly important under civil-law methodology.

13. What Is the Legal Nature of Crypto-Assets?

This is one of the central questions.

Traditional civil-law systems generally distinguish between:

Tangible property

Physical objects.

Intangible rights

Claims, receivables, intellectual property and other rights.

Crypto-assets create difficulty because a token is:

intangible;

electronically recorded;

transferable;

cryptographically controlled;

not necessarily a contractual claim against an identifiable debtor.

Consequently, different European legal systems may classify the asset differently.

The English AA and D'Aloia decisions provide particularly developed reasoning on crypto-assets as property. (Bailii)

14. Is the Private Key the Asset?

An important distinction is:

Crypto-asset ≠ private key.

A private key is essentially a means of controlling or transferring the asset.

Therefore, a custodian may possess or control the private key without becoming the beneficial owner of the underlying crypto-assets.

This distinction becomes critical when:

the custodian becomes insolvent;

the customer's account is frozen;

the custodian's creditors seek recovery;

the private keys are lost;

assets are transferred without authorisation.

15. Custody vs Deposit

Traditional civil law has the concept of deposit.

A conventional deposit generally involves:

delivery of a thing;

custody;

obligation to return;

preservation of the deposited thing.

Crypto custody does not necessarily fit this model.

For example, the French Paymium litigation specifically considered whether the contractual relationship could be treated as a Civil Code deposit and found the classification problematic because of the nature of the platform arrangement and the contractual mechanics. (Cour de Cassation)

Therefore:

Calling a crypto platform a “custodian” does not automatically mean that every national Civil Code rule concerning physical deposits applies.

16. Contractual Duties of a Crypto Custodian

A custodian may have contractual duties concerning:

Security

authentication;

two-factor authentication;

withdrawal controls;

wallet security;

private-key protection;

monitoring.

Operational performance

correctly executing instructions;

maintaining account records;

processing withdrawals;

preventing unauthorised transfers.

Information

informing customers about security risks;

notifying customers of suspicious activity;

explaining withdrawal restrictions.

Restitution

returning crypto-assets when contractually required.

17. Unauthorised Transfer

Suppose:

Customer owns 10 BTC.
Hacker gains access to the account.
Hacker transfers 10 BTC to another wallet.

The legal questions include:

A. Was there a valid customer instruction?

If not, the custodian may have breached its contractual obligations.

B. Was the transfer technically authenticated?

Authentication does not necessarily establish substantive consent.

C. Was the customer negligent?

For example:

leaked password;

compromised email;

failure to use available 2FA;

malware;

unsafe device.

D. Did the custodian comply with the contractual security system?

E. Was the transfer foreseeable?

F. Did the custodian have a duty to stop it?

These questions were central to the French Paymium litigation. (Cour de Cassation)

18. Customer Negligence

Crypto custody creates an unusual problem:

Security responsibilities are often divided.

The platform may control:

withdrawal infrastructure;

exchange systems;

authentication;

wallet architecture.

The customer may control:

email;

password;

device;

2FA;

recovery credentials.

Consequently, a court may need to apportion responsibility.

The Paymium decision is particularly instructive because the claimant had access to a two-factor authentication mechanism but did not use it, while the court found no demonstrated platform negligence on the facts. (Cour de Cassation)

19. Cybersecurity Duty

A custodian may face civil liability where it fails to implement security measures required by:

contract;

applicable financial regulation;

MiCA;

national law;

general professional standards.

But cybersecurity liability should not be treated as strict liability for every hack.

The claimant normally must establish a legally relevant failure.

Therefore:

Hack ≠ automatic custodian liability.

20. Loss of Private Keys

Another major dispute is:

Who bears the loss when a private key is permanently lost?

Possible legal positions include:

Custodian responsible

If the custodian had exclusive responsibility for key management.

Customer responsible

If the customer retained responsibility for private keys.

Shared responsibility

If the custody model distributed security responsibilities between both parties.

The contract and technical architecture become decisive.

21. Wrongful Freezing of Crypto-Assets

A crypto platform may freeze an account because of:

AML concerns;

sanctions;

suspected fraud;

court order;

law-enforcement request;

regulatory requirements;

internal risk controls.

The customer may then claim:

breach of contract;

unlawful interference;

damages;

restitution;

declaration of ownership.

The platform may respond that freezing was:

contractually permitted;

legally required;

necessary for compliance.

Thus, the dispute becomes a balance between:

customer property/contractual rights

and

regulatory compliance obligations.

22. Custodian Insolvency

This is perhaps the most important civil-law question.

Suppose:

Customer deposits €500,000 worth of Bitcoin with Exchange X.
Exchange X becomes insolvent.

The key question becomes:

Is the customer the owner of identified crypto-assets?

or

Does the customer merely have a personal contractual claim against the exchange?

The difference is enormous.

If the customer has a proprietary interest:

the assets may potentially be segregated from the insolvency estate.

If the customer only has a personal claim:

the customer may rank as an ordinary creditor, subject to applicable insolvency law.

MiCA's custody framework is therefore highly significant for future European insolvency litigation.

23. Tracing Crypto-Assets

Blockchain technology creates a distinctive evidentiary environment.

Traditional property litigation asks:

Where did the physical asset go?

Crypto litigation asks:

Which blockchain address received the relevant tokens, and who controlled that address?

A claimant may therefore use:

blockchain transaction histories;

wallet addresses;

exchange records;

IP information;

KYC information;

transaction timestamps;

expert blockchain analysis.

D'Aloia demonstrates that blockchain tracing can support proprietary litigation, but the claimant must still prove the connection between the original assets and the assets held by the defendant. (ZoomLaw)

24. Following vs Tracing

This distinction is essential for exams.

Following

The same crypto-assets move:

Wallet A → Wallet B → Wallet C

The claimant attempts to follow the same assets.

Tracing

The original asset is exchanged or transformed:

Crypto → Fiat → Bank account

The claimant seeks to trace the value into substitute property.

D'Aloia specifically considered the distinction between following and tracing. (ZoomLaw)

25. Constructive Trusts and Civil-Law Caution

English cases such as D'Aloia may use:

constructive trust;

equitable tracing;

unjust enrichment;

proprietary injunction.

These are common-law/equitable concepts.

A continental civil-law court would not necessarily reproduce those doctrines in exactly the same form.

Instead, the relevant legal mechanisms may involve:

ownership;

restitution;

unjust enrichment;

contractual restitution;

revindication;

wrongful enrichment;

provisional measures.

Therefore, English crypto cases should be used comparatively rather than described as European civil-law authorities.

26. MiCA and Civil Liability

MiCA primarily establishes a regulatory framework, including rules concerning authorised crypto-asset service providers.

Its importance for private litigation is indirect as well as direct.

Regulatory requirements can help establish what a professional crypto provider was expected to do.

For example:

Regulatory standard → contractual duty → breach → civil liability

But the exact private-law consequences depend upon the relevant national legal system and the particular provision involved.

27. Regulatory Status of the Custodian

A court may ask:

Was the provider authorised?

Was it registered?

Did it provide custody lawfully?

Did it fall within a transitional regime?

Was the service provided cross-border?

Was reverse solicitation involved?

French courts have already dealt with disputes concerning registration of digital-asset service providers. A 2022 Paris Court of Appeal decision examined the French registration regime for digital-asset custodians and exchange services. (Cour de Cassation)

In 2026, the Paris judicial court also applied MiCA in a case involving an unauthorised website offering crypto-asset custody and trading services in France and ordered measures to block access to the unlawful service. (Cour de Cassation)

28. Valuation of Damages

Cryptocurrency creates a difficult damages question.

Suppose:

5 BTC are stolen;

Bitcoin is €40,000 on the date of theft;

€70,000 when the lawsuit begins;

€100,000 at judgment.

What is the correct compensation?

Possible approaches depend on national law and the cause of action.

The court may consider:

date of loss;

date of breach;

date of judgment;

replacement cost;

actual loss;

lost opportunity;

mitigation;

restitution of the asset itself.

The Bitstamp litigation illustrates the difficulty because the claimant attempted to recover not only the stolen crypto-assets but also a much higher amount based on a later peak valuation. (Cour de Cassation)

29. Lost Investment Opportunity

A claimant may argue:

“If the custodian had not lost my cryptocurrency, I would have sold it at the market peak.”

That does not automatically establish damages.

The claimant may need to prove:

a real opportunity;

sufficient likelihood of exercising it;

causation;

reasonable certainty of loss.

Speculative appreciation is generally more difficult to recover than the proven value of the asset itself.

30. Consumer vs Institutional Customer

The legal position can differ depending on whether the customer is:

Consumer

Greater protection may arise under:

consumer law;

unfair-terms legislation;

EU jurisdiction rules;

mandatory information requirements.

Professional/institutional customer

The parties may have:

sophisticated contractual terms;

negotiated liability allocation;

arbitration clauses;

sophisticated custody arrangements;

contractual limitation clauses.

Therefore, the same cybersecurity failure can generate different legal consequences depending on the contractual context.

31. Cross-Border Jurisdiction

Crypto-assets are inherently transnational.

Example:

Customer: France
Custodian: Germany
Exchange: Netherlands
Blockchain: globally distributed
Hacker: unknown
Bank account: Luxembourg

The court must determine:

jurisdiction;

applicable law;

whether provisional relief can be obtained;

recognition and enforcement;

location of the relevant crypto-assets;

identity of wallet controllers.

The D'Aloia litigation demonstrates the importance of cross-border disclosure and jurisdictional mechanisms in cryptoasset disputes. (Bailii)

32. Provisional Remedies

Because crypto-assets can be transferred almost instantaneously, ordinary damages litigation may be insufficient.

Courts may therefore consider:

freezing orders;

proprietary injunctions;

asset preservation orders;

disclosure orders;

Norwich Pharmacal-type relief in common-law systems;

interim seizure;

orders directed at exchanges.

AA v Persons Unknown is a leading illustration of proprietary injunctive protection for Bitcoin. (Bailii)

33. Custodian's Defences

A crypto custodian may argue:

1. Authorised transaction

The transfer complied with the customer's instructions.

2. Customer negligence

The customer failed to protect:

passwords;

email;

private keys;

2FA;

devices.

3. Contractual exclusion

The contract allocates particular risks to the customer.

4. Third-party hacking

The loss was caused by an external criminal.

5. Regulatory obligation

The account was frozen because of AML/sanctions requirements.

6. Causation

Even if there was a security failure, it did not cause the loss.

7. Mitigation

The customer failed to take reasonable steps to reduce the loss.

34. Custodian's Possible Liability

Conversely, the claimant may argue:

inadequate cybersecurity;

failure to follow contractual security procedures;

failure to detect abnormal activity;

failure to stop suspicious transfers;

failure to preserve assets;

failure to maintain appropriate controls;

unauthorised transfer;

breach of custody obligations;

misleading information;

regulatory non-compliance.

The French Paymium case demonstrates that courts will examine the actual contractual and technical arrangements, rather than simply assuming that every crypto platform owes the same security obligations. (Cour de Cassation)

35. Crypto Custody and Consumer Protection

Where the customer is a consumer, additional issues can include:

unfair contractual terms;

transparency;

unilateral modification clauses;

liability exclusions;

mandatory dispute-resolution provisions;

jurisdiction clauses;

information obligations.

A platform cannot necessarily contract out of mandatory consumer protections.

36. Crypto-Asset Custody and Data Protection

Custodians normally process substantial personal data:

identity;

address;

KYC information;

transaction history;

IP addresses;

wallet information;

banking information.

A security breach can therefore create two separate categories of liability:

Crypto-asset loss

Loss of cryptocurrency.

Personal-data breach

Unauthorised disclosure or compromise of personal information.

The two claims should not automatically be conflated.

37. Regulatory vs Civil Liability

A crucial exam distinction is:

Regulatory violation

The provider violated a financial/crypto regulation.

Civil liability

The provider owes damages to the customer.

A regulatory breach may be powerful evidence of wrongdoing, but it does not necessarily mean that every customer automatically receives damages.

The claimant still needs an appropriate civil cause of action and proof of causation and loss.

38. European Civil-Law Approach

A continental civil-law court is likely to analyse the dispute through several traditional concepts:

Contract

What did the parties agree?

Good faith

Was the contract performed honestly and appropriately?

Custody

Was the provider obliged to safeguard and return assets?

Ownership

Who legally owns the crypto-assets?

Restitution

What must be returned after an unauthorised transfer?

Unjust enrichment

Has one party received value without legal justification?

Tort

Did the provider negligently cause damage?

Causation

Did the provider's breach actually cause the loss?

Damages

What loss is legally recoverable?

39. Case-Law Comparison

40. Key Legal Principles

Crypto-assets can possess legally protectable proprietary value.

Custody does not necessarily transfer ownership to the custodian.

A crypto-custody contract should not automatically be equated with a traditional Civil Code deposit.

Contractual allocation of cybersecurity responsibilities is extremely important.

Customer negligence may affect custodian liability.

A hacking event does not automatically establish custodian negligence.

Unauthorised transfers can generate contractual, restitutionary and proprietary claims.

Blockchain records can provide valuable tracing evidence.

Following and tracing are legally distinct concepts.

Proprietary remedies may be particularly important because crypto-assets can be rapidly dissipated.

Crypto exchanges can become defendants in tracing and recovery proceedings.

Custodian insolvency creates difficult ownership-versus-personal-claim questions.

MiCA provides an important regulatory framework for custody.

Regulatory non-compliance does not automatically equal civil damages.

Damages valuation is difficult because cryptocurrency prices are volatile.

Lost-profit claims require proof and cannot simply be based on the highest historical price.

Cross-border jurisdiction is particularly important because blockchain transactions are transnational.

Consumer status can strengthen mandatory protections.

Data-security claims may exist alongside crypto-asset claims.

National civil law remains central to contract, ownership, restitution, causation and damages.

41. Important Exam Distinction

Traditional custody

Thing delivered → custodian possesses → custodian protects → custodian returns

Crypto custody

Crypto-asset/account → cryptographic control → platform infrastructure → contractual instructions → blockchain transfer

Therefore:

Crypto custody is not merely digital warehousing. It is a combination of contractual, technological, proprietary and regulatory relationships.

42. Ultra-Basic Revision Keywords

Crypto-assets → Custody → MiCA → CASP → Wallet → Private key → Ownership → Contract → Deposit → Safekeeping → Exchange → Unauthorised transfer → Hacking → Cybersecurity → Customer negligence → Custodian negligence → Restitution → Unjust enrichment → Property → Proprietary injunction → Freezing order → Tracing → Following → Blockchain evidence → Insolvency → Segregation → Damages → Valuation → Consumer protection → Jurisdiction → Cross-border enforcement.

Conclusion

European crypto-asset custody litigation is developing from traditional civil-law concepts rather than replacing them. The central questions are who owns the crypto-assets, what the custodian contract requires, who controlled the relevant security credentials, whether the transfer was authorised, whether either party was negligent, and what proprietary or personal remedy follows.

The most useful continental European authorities presently include the French Paymium/Blockchain.io and Bitstamp litigation, while AA, D'Aloia and Fetch.AI provide important comparative authorities on crypto-assets as property, tracing, hacking and protective remedies. The French cases are particularly valuable because they show that courts examine the actual contractual custody structure and allocation of cybersecurity responsibilities, rather than automatically applying the traditional legal concept of physical deposit. (Cour de Cassation)