Any modification creates a detectable different hash
Cuando un juez ordena la incautación de un teléfono, ese dispositivo deja de ser un objeto cotidiano para convertirse en un archivo frágil de la conducta humana. La especialista en informática forense Magalí Dos Santos explicó cómo los sistemas judiciales preservan y analizan la evidencia digital, recordándonos que la verdad en la era moderna no reside en testimonios ni documentos en papel, sino en los rastros invisibles que dejamos en nuestros dispositivos. La integridad de esa verdad depende de protocolos estrictos, herramientas especializadas y una cadena de custodia que garantice que nadie ha alterado lo que el aparato sabe.
- La evidencia digital es tan volátil que encender un teléfono incautado puede destruir información clave antes de que un perito la examine.
- Cualquier conexión a internet tras la incautación puede desencadenar restauraciones remotas o borrados automáticos que anulan el valor probatorio del dispositivo.
- El sistema de hash actúa como un sello matemático infalsificable: cualquier alteración, por mínima que sea, produce un código completamente distinto y delata la manipulación.
- Los dispositivos Apple representan un obstáculo crítico para las investigaciones, ya que desbloquearlos sin el código puede llevar años, paralizando causas que dependen de esos datos.
- La cadena de custodia —el registro de cada persona que tocó el dispositivo— determina si la evidencia tiene validez judicial o se convierte en papel sin valor.
Cuando un juez ordena la incautación de un teléfono, ese dispositivo se convierte en algo mucho más frágil de lo que la mayoría imagina. La especialista en informática forense Magalí Dos Santos explicó a periodistas cómo los tribunales preservan y analizan la evidencia digital contenida en estos aparatos, y por qué la acción más mínima —incluso encender o apagar el teléfono— puede comprometer una investigación entera.
La evidencia digital es volátil por naturaleza: puede alterarse o contaminarse sin que nadie lo intente. La respuesta a este desafío reside en el concepto de hash, un código único generado a partir del contenido de un archivo. Mientras el archivo no cambie, el hash permanece idéntico; basta modificar un solo carácter para que se vuelva irreconocible. Este principio no solo sostiene las investigaciones criminales, sino que también permite a cualquier persona verificar si sus propios datos han sido manipulados.
Una vez incautado el dispositivo —generalmente en allanamientos vinculados a delitos como explotación infantil o narcotráfico— el manejo se vuelve estrictamente regulado. El teléfono debe colocarse en una bolsa antiestática, mantenerse apagado, en modo avión y sin SIM. Cualquier conexión posterior puede activar cambios remotos que destruyan la evidencia. El análisis lo realizan peritos especializados, quienes crean una copia forense exacta del dispositivo y generan un hash irrepetible que garantiza la integridad de los datos ante el tribunal.
Los procedimientos técnicos son estándares internacionales. Los especialistas utilizan bloqueadores de escritura para evitar modificaciones durante el análisis, y software propietario como Cellebrite UFED para extraer la información. Sin embargo, los dispositivos Apple representan un obstáculo mayor: sin el código de acceso, desbloquear un iPhone puede llevar años. Todo el proceso debe acompañarse de una cadena de custodia que registre a cada persona que tocó el aparato; sin ese documento, la evidencia pierde validez legal.
Lo que hace tan poderosa a la informática forense es lo que la mayoría de los usuarios ignora: sus teléfonos registran geolocalización de forma constante, historial de encendidos, comunicaciones y actividad en segundo plano. Incluso tras un reseteo de fábrica, gran parte de esos datos es recuperable. Un teléfono puede reconstruir los movimientos de una persona, sus contactos y su cronología con una precisión que ninguna otra fuente puede igualar. La reciente decisión del juez Ariel Lijo de avanzar con el análisis forense del teléfono de un contratista vinculado a un funcionario argentino ilustra cuán central se ha vuelto esta disciplina en las investigaciones modernas.
When a judge orders a phone seized, the device becomes something far more fragile than most people realize. A forensic specialist named Magalí Dos Santos, who works at the intersection of technology and criminal investigation, explained to journalists how courts preserve and analyze the digital evidence locked inside these devices—and why the smallest action, even turning a phone on or off, can compromise an entire investigation.
Digital evidence is volatile by nature. It can be altered, contaminated, sometimes without anyone intending to do so. The moment a device enters the judicial system, it transforms into a critical piece of evidence, regardless of what it contains. Dos Santos emphasized that this fragility extends beyond courtrooms. A person protecting their own files, or trying to prove a document hasn't been tampered with, faces the same challenge: how do you preserve the integrity of digital information? The answer lies in something called a hash—a unique code generated from a file's contents. As long as the file remains unchanged, the hash stays identical. Alter even a single character, and the hash becomes unrecognizable. This principle allows anyone to verify whether their data has been modified over time, making digital evidence a tool for everyday security, not just criminal cases.
Once a phone is seized under judicial order, usually during a raid connected to crimes ranging from child exploitation to drug trafficking, the handling becomes strictly regulated. The device must be placed in an antistatic bag to shield it from electromagnetic interference and environmental damage. It cannot be powered on. It must be placed in airplane mode, have its SIM card removed, and ideally have its battery removed entirely. Any internet connection after seizure can trigger remote changes—backup restoration, data deletion—that destroy the evidence's value. The police execute the seizure order, but the actual analysis falls to digital forensics specialists who understand the technical landscape.
The core procedure involves creating a forensic copy, an exact image of everything on the device. During this process, a hash code is generated—unique and unrepeatable. Dos Santos was categorical on one point: there is no way to alter that hash without detection. Any modification to the underlying data produces a different hash immediately. The only way to hide tampering would be to change the hash itself, but that would require changing the data, which would change the hash again. It's a closed loop. This is why forensic copies hold up in court. The validity of digital evidence depends entirely on the device remaining untouched after seizure.
The technical procedures governing this work are international standards. They're the same in Argentina, the United States, or anywhere else. When extracting data, forensic specialists use write-blockers—devices that prevent any modification to the phone during analysis. The phone connects to specialized software, typically Cellebrite UFED, which generates detailed reports after extraction. There are no free tools for this work. The software is expensive, proprietary, and essential. But even the best tools have limits. Apple devices present a major obstacle. Without the correct code, unlocking an iPhone can take years, creating significant delays in investigations that depend on the data inside.
Every device that moves through the system must be accompanied by a chain-of-custody document. This record lists every person who touched the phone—their name, surname, identification number. It creates a traceable path from seizure to analysis to courtroom, ensuring the evidence's legitimacy. Without it, the data becomes legally worthless, no matter how accurate the forensic work.
What makes digital forensics so powerful in criminal cases is what most users don't know their phones are recording. A device stores geolocation data constantly, even when a user believes they've disabled it. It logs every power-on and power-off. It preserves browsing history, communications, and countless background activities. Even after a factory reset or format, most of this data remains recoverable. A phone can reconstruct a suspect's movements, their contacts, their timeline—information that often proves decisive in court. The recent decision by Judge Ariel Lijo to proceed with forensic analysis of a contractor's phone linked to a government official in Argentina underscores how central this work has become to modern investigations. Digital evidence, handled correctly, can tell a story that no other source can.
Citações Notáveis
Digital evidence is totally volatile, fragile, can be altered, contaminated, sometimes without intention— Magalí Dos Santos, digital forensics expert
A device constantly stores geolocation data in the background, even when users believe they've disabled it— Magalí Dos Santos, digital forensics expert
A Conversa do Hearth Outra perspectiva sobre a história
Why does turning a phone on or off matter so much? Isn't the data already there?
Every action creates new digital traces. When you power on a device, the system generates logs, timestamps, connection attempts. These are real data that didn't exist before. For a judge to trust the evidence, they need to know exactly what was on the phone at the moment it was seized—not what happened after.
So if someone's phone is seized and then connected to the internet, the whole investigation falls apart?
Not entirely, but it becomes severely compromised. Remote changes can happen instantly—backups restored, files deleted, accounts accessed. The forensic copy might still exist, but now you can't prove what was original and what was added later. The chain breaks.
This hash code sounds like magic. Can't someone with enough skill forge it?
That's the elegant part. You can't forge a hash without changing the underlying data. And if you change the data, the hash changes automatically. It's not magic—it's mathematics. You'd have to alter the data and then somehow make the hash match the original, which is computationally impossible.
What about Apple devices? Why are they so difficult?
Apple's encryption is genuinely strong. Without the passcode, you're essentially locked out. Brute-force attempts can take years. It's not a flaw in forensic technique—it's the device itself resisting access. Some investigations just wait. Others don't get the answers they need.
If all these protocols are international, why does it matter where the phone is analyzed?
The protocols are the same, but the people applying them aren't. A specialist in Buenos Aires follows the same steps as one in New York. But their skill, their equipment, their access to the right software—that varies. And the legal system interpreting the results is always local.