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In recent years, the technological revolution has radically changed the way we communicate and, with it, the way we collect and evaluate evidence in legal proceedings. Tools such as WhatsApp, email and digital signatures, initially designed to streamline document management and personal and professional communications, have become key players in litigation, internal investigations and audits. But do they really provide the legal certainty they appear to offer? Are we prepared to face the challenges posed by their use in a scenario where artificial intelligence (AI) now allows not only messages to be edited, but also conversations to be simulated and even digital identities to be cloned?
From email to WhatsApp
This question takes us back to the recent past, when courts first began grappling with the challenges of admitting email communications as evidence. The main and recurring stumbling block was proving issues such as the true sender, the integrity of the document, and the absence of tampering. The usual protocol required an IT expert to certify, either beforehand or after a challenge, the authenticity and origin of the message.
A similar debate is unfolding today, focused on the evidentiary challenges of WhatsApp messages. Now, the ease with which screenshots can be obtained and submitted to legal proceedings contrasts with the growing sophistication of techniques for the falsification of conversations. However, contrary to what might be expected (a strengthening of technical and procedural guarantees), the recent trend of the Spanish Supreme Court has been to relax evidentiary admissibility requirements: if there is no specific challenge, the authenticity of the messages is usually presumed, with the burden of proving manipulation or falsification falling on the defence.
The fundamental issue is that the problems detected years ago regarding email — lack of technical verification, traceability challenges, content manipulation — remain fully relevant to instant messaging and, if anything, have become even more serious with the exponential increase in tools for creating “deepfakes” and imitative audio recordings.
Therefore, the plausible appearance of information should not replace the duty to demand robust protocols that guarantee its authenticity.
Digital signatures: a solution or a new source of vulnerability?
Alongside the rise of WhatsApp and similar applications, the widespread adoption of digital signatures was hailed as a solution to the challenges of authenticity and non-repudiation in electronic documents.
On the surface, a digital signature issued by a qualified provider should shield electronic documents from their manipulation and impersonation. However, the reality in companies and law firms has shown that technology, without effective internal protocols, can be as vulnerable as traditional methods: certificates in the hands of unauthorised personnel, shared passwords and a lack of access and usage logs are common errors that compromise the validity and traceability of electronic signatures.
Comparing our context with other international models helps put these challenges into perspective. In Japan, for example, traditional identification using the “hanko” (personal seal) continues to prevail in everyday life and in many legal procedures, over electronic signatures, precisely because of the trust that society places in tangible systems that are directly controlled by the individual.
Artificial intelligence: when technology multiplies evidentiary risk
The emergence of artificial intelligence systems capable of fabricating messages, emails, audio files or images that simulate reality to unsuspected extremes reopens the debate on where to set the threshold of reliability required for digital evidence. The latest rulings, together with the entry into force of the AI Act in the European Union, emphasise that digital evidence must always be subject to human verification, auditing and traceability mechanisms. Only in this way can the presumption of innocence be protected and effective judicial protection ensured in the face of automated decisions or evidence generated by opaque algorithms.
Practical recommendations
To avoid exposure to the risks associated to excessive flexibility in the admissibility of digital evidence, law firms and companies must adopt preventive and corrective measures:
- Implement strict internal protocols for the use and custody of electronic signatures.
- Require, whenever there are reasonable doubts, the opinion of an IT expert on emails and digital exchanges.
- Prioritise the preservation of metadata, access logs and original documents, including the relevant chains of custody.
- Schedule regular audits of digital procedures and provide legal training to staff on the risks associated with AI and evidence automation.
Technology: at the service of legal certainty
Although digitalisation has exponentially increased the speed and ease of communications and procedures, it is crucial to remember that the mere appearance of truth must never supplant the need for objective legal safeguards. WhatsApp messages, emails and digital signatures must be subject to rigorous authenticity and traceability checks, as befits a state governed by the rule of law. We must demand, as we did decades ago, reinforced safeguards that truly protect the parties against manipulation, impersonation or errors in an automated system.
It is only under these conditions that technology can effectively support legal certainty and justice.
Shameem Hanif Truszkowska
Vilá Abogados
For more information please contact :
29th August 2025
