Asymmetric Encryption
A system using dual keys for secure encryption and digital signatures.
Asymmetric encryption is the cornerstone of blockchain technology. Unlike symmetric encryption (where the same key is used to lock and unlock), asymmetric encryption uses two related but different keys. The Public Key acts like your mailbox address (anyone can see it and send you mail), while the Private Key is the physical key to the mailbox that only you possess. This allows for secure communication and digital signatures without ever having to share a master password.
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✅ 검증된 기술 정보
- • Asymmetric encryption uses two different keys: a public key and a private key.
- • The public key can be shared openly with anyone.
- • The private key must be kept secret by the owner.
- • Data encrypted with the public key can only be decrypted with the matching private key.
- • Digital signatures are created using the private key and verified with the public key.
- • Blockchains like Bitcoin and Ethereum use Elliptic Curve Cryptography (ECC) for security.
graph LR
Center["Asymmetric Encryption"]:::main
Pre_cryptography["cryptography"]:::pre --> Center
click Pre_cryptography "/terms/cryptography"
Pre_mathematics["mathematics"]:::pre --> Center
click Pre_mathematics "/terms/mathematics"
Rel_public_key["public-key"]:::related -.-> Center
click Rel_public_key "/terms/public-key"
Rel_private_key["private-key"]:::related -.-> Center
click Rel_private_key "/terms/private-key"
Rel_elliptic_curve_cryptography_ecc["elliptic-curve-cryptography-ecc"]:::related -.-> Center
click Rel_elliptic_curve_cryptography_ecc "/terms/elliptic-curve-cryptography-ecc"
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classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
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🧒 5살도 이해할 수 있게 설명
🔐 Imagine a magic padlock that comes with two keys. One key can ONLY lock the box (the [Public Key](/ko/terms/public-key)), and the other key can ONLY unlock it (the [Private Key](/ko/terms/private-key)). You can give the 'locking key' to everyone in the world, so they can send you secret boxes. But only you can open them because you kept the 'unlocking key' hidden under your pillow.
🤓 Expert Deep Dive
The security of asymmetric encryption relies on Trapdoor Functions—mathematical problems that are easy to compute in one direction but virtually impossible to reverse without a 'trapdoor' (the private key). Modern blockchains primarily use Elliptic Curve Cryptography (ECC), specifically the secp256k1 curve for Bitcoin and Ethereum, rather than older RSA methods. ECC provides equivalent security to RSA but with significantly smaller key sizes (256-bit ECC vs 3072-bit RSA), making transaction processing much more efficient for nodes. It enables two critical functions: Encryption (securing data) and Digital Signatures (proving ownership of an address without revealing the private key).