---
title: Public and private key
url: "https://www.unknowngravity.com/en/glosario/clave-publica-clave-privada"
site: Unknown Gravity
published: "2025-06-11T06:55:48+00:00"
modified: "2026-07-15T10:51:27+00:00"
language: en-US
description: "Public and private keys are a pair of interrelated cryptographic elements that operate on the principle of asymmetric cryptography, a fundamental pillar in the security architecture of blockchain…"
section: "Home > Public and private key"
---

# Public and private key

GLOSSARY · BLOCKCHAIN & WEB3

A pair of cryptographic keys used to secure and sign blockchain transactions.

WHAT IS IT? · FOR DUMMIES

Imagine that you have a safe with a slot for receiving cards.

The **public key** is like your address: anyone can use it to send you things.

But to open the box and access what they sent you, you need a **private key**, which is like a secret key. No one else should know that key.

If you lose it, you can't open the box. This is how many technologies such as cryptocurrencies or encrypted messages work.

WHAT IS IT? · PRO

Public and private keys are a pair of interrelated cryptographic elements that operate on the principle of **asymmetric cryptography**, a fundamental pillar in the security architecture of blockchain, cryptocurrency, digital identity and multiple Web3 systems.

The **Private** Key is a secret fact known only to the owner, which allows **sign transactions**, access wallets and demonstrate ownership of digital assets or encrypted data.

The Key **Public**, derived mathematically from the private one using unidirectional cryptographic functions, acts as an identifier open to the public: it is the address to which others can send assets, validate signatures or interact.

This model allows authentication without intermediaries, eliminating the need to trust third parties to verify identity or ownership.

The system is secure as long as the private key remains protected, since its loss or leak can have irreversible consequences. In addition, this key pair is integrated into protocols such as SSL/TLS, public key infrastructure (PKI) and in the validation of smart contracts on blockchains such as Ethereum or Bitcoin.

The mathematical robustness of this scheme has made it a global standard for ensuring privacy, integrity and traceability in decentralized digital environments.

## 01 / Key points

- They are two unique and mathematically linked keys.
- The private key **should never be shared**; gives full access
- The public key can be freely shared; it works as an address
- They allow **sign and verify** digitally documents and transactions
- They are used in blockchain, cryptocurrency, secure messaging and authentication

## 02 / Advantages

- **Robust cryptographic security** based on mathematical algorithms
- **Privacy and Control** Total amount of digital assets or identities
- It allows the use of **digital signatures** and passwordless authentication
- Technical basis for trading wallets, smart contracts and tokens
- **Does not require intermediaries**, facilitating decentralized systems

## 03 / Disadvantages

- **Loss of private key** involves total loss of access
- **Technical complexity** for users not familiar with cryptography
- Risk of **Phishing or malware** if the private key is not properly protected
- Being an asymmetric system, the **revoking keys** may require complex solutions
- **No automatic recovery**, unlike traditional centralized systems

RELATED CONCEPTS

[Digital signature](/en/glosario/firma-digital) [Hash](/en/glosario/hash) [Wallet](/en/glosario/wallet) [Smart contract](/en/glosario/smart-contract) [Cryptocurrency](/en/glosario/criptomoneda)

KEEP LEARNING

[How to protect your digital assets in the cryptocurrency world](/en/articulos/como-proteger-tus-activos-digitales-criptomonedas) [Smart contracts: good practices that will save you from a hack](/en/articulos/contratos-inteligentes-bien-hechos-buenas-practicas-que-te-salvaran-de-un-hack) [Decentralization in Blockchain: Transformation, Benefits and Future](/en/articulos/la-importancia-de-la-descentralizacion-en-blockchain) [Smart Contracts without surprises: common mistakes in Solidity and how to avoid them](/en/articulos/smart-contracts-soliditys-errores-comunes-y-como-evitarlos) [Complete Guide to Launching a Security Token Offering (STO) in Europe: Everything You Need to Know](/en/articulos/guia-completa-lanzar-security-token-offering-sto-europa-todo-lo-que-debes-saber)

RELATED SERVICES

[Digital Identity Management](/en/servicios/blockchain-para-gestion-de-identidades-digitales) [Development of smart contracts](/en/servicios/company-development-smart-contracts) [Development for Ethereum (EVM)](/en/servicios/desarrollo-para-ethereum-evm) [White label tokenization platform](/en/servicios/plataforma-tokenizacion-marca-blanca)

[Full glossary](/en/glosario)

This entry is informative. It is not legal, tax or investment advice. The rules cited change: check the current version on [BOE](https://www.boe.es) and [EUR-Lex](https://eur-lex.europa.eu).