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	"title": "What is Asymmetric Encryption? | IBM",
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	"plain_text": "https://www.ibm.com/think/topics/asymmetric-encryption\n\nWhat is Asymmetric Encryption? | IBM\n\nBy Annie Badman, Matthew Kosinski\n\nPublished: 2024-08-08 · Archived: 2026-10-14 02:02:39 UTC\n\nAuthors\n\nAsymmetric encryption is an encryption method that uses two different keys—a public key and a private key—to\n\nencrypt and decrypt data. It’s generally regarded as more secure, though less efficient, than symmetric encryption.\n\nAlmost everything people do on their computers, phones and, increasingly, IoT devices relies on encryption to\n\nprotect data and ensure secure communications.\n\nEncryption is the process of transforming readable plaintext into unreadable ciphertext to mask sensitive\n\ninformation from unauthorized users. According to the IBM Cost of a Data Breach report, organizations that use\n\nencryption can reduce the financial impact of a data breach by over USD 200,000.\n\nAsymmetric encryption, also known as public key cryptography or asymmetric cryptography, is one of two\n\nmain methods of encryption alongside symmetric encryption.\n\nAsymmetric encryption works by creating a pair of keys, one public and one private. Anyone can use a public key\n\nto encrypt data. However, only the holders of the corresponding private key can decrypt that data.\n\nThe main advantage of asymmetric encryption is that it eliminates the need for a secure key exchange, which most\n\nexperts regard as the main point of insecurity for symmetric encryption.\n\nHowever, asymmetric encryption is notably slower and more resource intensive than symmetric encryption. For\n\nthis reason, organizations and messaging apps increasingly rely on a hybrid encryption method that uses\n\nasymmetric encryption for secure key distribution and symmetric encryption for subsequent data exchanges.\n\nWhat’s the difference between asymmetric and symmetric encryption?\n\nSymmetric encryption differs from asymmetric encryption because it uses a single key to encrypt and decrypt\n\ndata, whereas asymmetric encryption uses two keys: a public key and a private key.\n\nUsing a shared key means symmetric encryption is generally faster and more efficient but also more vulnerable to\n\nthreat actors. Symmetric encryption requires a key exchange, in which the communicating parties agree on a\n\nshared secret key. Hackers can intercept the key during this exchange, allowing them to decrypt subsequent\n\nmessages.\n\nTypically, organizations choose symmetric encryption when speed and efficiency are crucial or when dealing with\n\nlarge volumes of data over a closed system, such as in a private network. They choose asymmetric encryption\n\nwhen security is paramount, such as encrypting sensitive data or securing communication within an open system,\n\nsuch as the internet.\n\nPage 1 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nAsymmetric encryption also enables the use of digital signatures, which verify the authenticity and integrity of a\n\nmessage to ensure it hasn't been tampered with during transmission.\n\nAdvanced Encryption Standard (AES) is a symmetric encryption algorithm often hailed as the gold standard for\n\ndata encryption. Offering robust security with key lengths of 128, 192 or 256 bits, AES is widely adopted by\n\norganizations and governments worldwide, including the US government and the US National Institute of\n\nStandards and Technology (NIST).\n\nThe latest tech news, backed by expert insights\n\nStay up to date on the most important—and intriguing—industry trends on AI, automation, data and beyond with\n\nthe Think newsletter. See the IBM Privacy Statement.\n\nAsymmetric encryption keeps data secure by using cryptographic algorithms to generate a pair of keys: a public\n\nkey and a private key. Anyone can use the public key to encrypt data, but only those with the right private key can\n\ndecrypt that data to read it.\n\nKeys function like complex codes needed to unlock a safe. Without the correct cryptographic key, users cannot\n\ndecode the encrypted data. Generally, the longer the key size, the higher the security. Asymmetric encryption is\n\nknown for having much longer key lengths than symmetric encryption, which contributes to its higher security.\n\nIn asymmetric encryption, the two keys serve different purposes:\n\nThe public key encrypts data or verifies digital signatures and can be freely distributed and shared.\n\nThe private key decrypts data and creates digital signatures but must stay secret to ensure security.\n\nThe security of public-key cryptography relies on keeping the private key confidential while freely sharing the\n\npublic key. The public key can only encrypt data, so it isn’t of much value to threat actors. And because users\n\nnever need to share their private keys, it greatly reduces the risk of hackers intercepting those much more valuable\n\nkeys.\n\nOnce the private and public keys are in place, individuals can exchange sensitive information. The sender encrypts\n\na message using the recipient's public key, and the recipient uses their private key to decrypt the information.\n\nThink of the process as similar to a locked mailbox: anyone can drop a letter into a mailbox, but only the owner\n\ncan unlock it and read the mail.\n\nAsymmetric encryption can also help ensure authentication. For instance, a sender can encrypt a message using\n\ntheir private key and send it to a recipient. The recipient can then use the sender's public key to decrypt the\n\nmessage, thereby confirming it was the original sender who sent it.\n\nAsymmetric encryption schemes are typically implemented through a public key infrastructure (PKI). A PKI is\n\na framework for creating, distributing and validating pairs of public and private key pairs.\n\nExamples of asymmetric encryption\n\nPage 2 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nTo understand how asymmetric encryption works, consider the following example of Bob and Alice.\n\n1. Alice wants to email Bob and ensure only he can read the message. She uses Bob's public key to encrypt\n\nher message.\n\n2. Bob receives the encrypted message and uses his private key to decrypt and read it.\n\n3. Because Bob is the only one with both corresponding keys, he can read the message, guaranteeing\n\nconfidentiality.\n\nNow, let's consider a scenario where Alice needs to prove her identity to Bob. She can use asymmetric\n\nencryption as a form of authentication.\n\n1. Alice uses her private key, a key that only she can access, to encrypt a message.\n\n2. Alice sends the encrypted message to Bob, who uses Alice's public key to decrypt it.\n\n3. Bob knows that only Alice could have sent the message, because only Alice possesses the private key that\n\nwas used to encrypt the message.\n\nIntegrating asymmetric and symmetric encryption\n\nOrganizations are increasingly combining symmetric and asymmetric encryption for security and efficiency. This\n\nhybrid process begins with a secure key exchange, where asymmetric encryption is used to securely exchange a\n\nsymmetric key.\n\nFor example:\n\n1. Alice generates a pair of public and private keys. She shares the public key with Bob.\n\n2. Bob generates a symmetric key.\n\n3. Bob uses Alice’s public key to encrypt the symmetric key, and then he sends the encrypted key to Alice. If\n\na threat actor intercepts the key in transit, they won’t be able to use it because they can’t decrypt it.\n\n4. Alice receives the encrypted key and uses her private key to decrypt it. Now, Alice and Bob have a shared\n\nsymmetric key.\n\nOnce shared, the symmetric key can efficiently handle all data encryption and decryption. For instance, a live\n\nvideo streaming service might use asymmetric encryption to secure the initial key exchange with a viewer. Then,\n\nthe site can use a symmetric stream cipher for real-time data encryption.\n\nAsymmetric encryption algorithms are the backbone of modern cryptosystems, providing the basis for secure\n\ncommunications and protecting sensitive data from unauthorized access.\n\nSome of the most significant asymmetric encryption algorithms include:\n\nRivest-Shamir-Adleman (RSA)\n\nElliptic Curve Cryptography (ECC)\n\nDigital Signature Algorithm (DSA)\n\nRivest-Shamir-Adleman (RSA)\n\nPage 3 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nRSA is an asymmetric encryption algorithm named after its inventors. It relies on the mathematical complexity of\n\nprime numbers to generate key pairs. It uses a public-private key pair for encryption and decryption, making it\n\nsuitable for secure data transmission and digital signatures.\n\nThe RSA algorithm frequently helps secure communication protocols such as HTTPS, SSH and TLS. Despite\n\nbeing developed in the 1970s, RSA remains widely used due to its robustness and security. Various applications\n\nrely on RSA, including secure email, VPNs and software updates.\n\nElliptic Curve Cryptography (ECC)\n\nECC is an asymmetric encryption method based on the mathematical properties of elliptic curves over finite\n\nfields. It offers robust security with shorter key lengths than other algorithms, which results in faster computations\n\nand lower power consumption.\n\nECC's efficiency makes it ideal for applications with limited processing power and battery life, such as mobile\n\napplications, secure messaging apps and IoT devices.\n\nDigital Signature Algorithm (DSA)\n\nThe Digital Signature Algorithm (DSA) allows organizations and individuals to create digital signatures that\n\nensure the authenticity and integrity of messages or documents.\n\nStandardized by NIST, DSA relies on the mathematical problem of the discrete logarithm and appears in various\n\nsecurity protocols. DSA is often used in applications that require secure document signing and verification,\n\nincluding software distribution, financial transactions and electronic voting systems.\n\nEncryption key management is the process of generating, exchanging and managing cryptographic keys to ensure\n\nthe security of encrypted data.\n\nThink of encryption like a safe: if you forget the code or it falls into the wrong hands, you risk losing access to\n\nyour valuables or having them stolen. Similarly, if organizations don't properly manage their cryptographic keys,\n\nthey can lose access to encrypted data or expose themselves to data breaches.\n\nFor example, Microsoft recently disclosed that a China-backed hacking group had stolen a critical cryptographic\n\nkey from its systems.1 This key allowed hackers to generate legitimate authentication tokens and access cloud-\n\nbased Outlook email systems for 25 organizations, including multiple US government agencies.\n\nTo protect against attacks like these, organizations often invest in key management systems. These services are\n\ncritical given that organizations frequently manage a complex network of cryptographic keys, and many threat\n\nactors know where to look for them.\n\nEncryption key management solutions often include features like:\n\nA centralized management console for encryption and encryption key policies and configurations\n\nEncryption at the file, database and application levels for on-premises and cloud data\n\nPage 4 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nRole- and group-based access controls and audit logging to help address compliance\n\nAutomated key lifecycle processes\n\nIntegration with the latest technologies, such as AI, to improve key management by using analytics and\n\nautomation\n\nDiffie-Hellman key exchange\n\nThe Diffie-Hellman key exchange is a core component of key management. It is a method that allows two parties\n\nto securely exchange cryptographic keys over public channels and generate a shared secret key for subsequent\n\nsecure communications.\n\nThe algorithm's security relies on the difficulty of solving the discrete logarithm problem. It appears in protocols\n\nlike SSL/TLS.\n\nWhatsApp uses Diffie-Hellman as part of the Signal Protocol to provide users with end-to-end encryption. This\n\nprotocol encrypts data before transferring it to another endpoint to prevent third-party tampering. Diffie-Hellman\n\nis also widely used in VPNs and secure email systems.\n\nWhen security is paramount, organizations lean on asymmetric encryption. Common asymmetric encryption use\n\ncases include:\n\nWeb browsing\n\nSecure communications\n\nDigital signatures\n\nAuthentication\n\nKey exchange\n\nBlockchain technology\n\nWeb browsing\n\nMost major browsers secure web sessions through protocols that rely significantly on asymmetric encryption,\n\nincluding Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), which enable HTTPS.\n\nThe browser obtains the website's public key from its TLS/SSL certificate while the website keeps its private key\n\nsecret. The initial handshake between browser and site then uses asymmetric encryption to exchange information\n\nand establish a secure session key.\n\nWith the secure session key established, the connection transitions to symmetric encryption for more efficient data\n\ntransmission.\n\nSecure communications\n\nAsymmetric encryption helps ensure that only intended recipients read emails and text messages.\n\nPage 5 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nProtocols like Pretty Good Privacy (PGP) use public-key cryptography to secure email communications. The\n\nsender encrypts the email with the recipient's public key, ensuring only the recipient can decrypt it with their\n\nprivate key.\n\nEnd-to-end encryption—a secure communication process that encrypts data before transferring it to another\n\nendpoint—also uses elements of asymmetric encryption.\n\nFor instance, messaging apps like Signal and WhatsApp leverage asymmetric encryption for key exchange and\n\nsymmetric encryption for message content. This process prevents intermediaries—and even service providers\n\nthemselves—from accessing plaintext data. Only the sender and the intended recipient can read the messages.\n\nDigital signatures\n\nDigital signatures are one of the most common and practical applications of asymmetric key cryptography. They're\n\ncritical for ensuring both authenticity and integrity.\n\nDigital signatures guarantee authenticity by confirming the document genuinely comes from the signer, much like\n\na physical signature would. They guarantee integrity by ensuring no one tampered with the document in transit.\n\nDigital signatures use asymmetric encryption to encrypt a file's hash with a private key. A hash is a string of\n\ncharacters that represents the document's data. If anyone alters the file, its hash changes, alerting users to the\n\ntampering.\n\nEncrypting the hash creates a signature that anyone can verify with the corresponding public key to ensure the\n\ndocument's origin and integrity.\n\nSoftware developers also use digital signatures to verify that their code hasn't been tampered with and to confirm\n\nits origin, helping to prevent the distribution of malicious software.\n\nAuthentication\n\nAsymmetric encryption can help systems authenticate users and websites.\n\nFor example, the Secure Shell Protocol (SSH) uses public-key cryptography to verify users trying to access\n\nremote servers. It also supports certificate authorities, which are third parties that issue digital certificates to verify\n\nthe authenticity of websites and other entities.\n\nKey exchange\n\nAsymmetric protocols like Diffie-Hellman and RSA can help users securely exchange cryptographic keys over an\n\ninsecure channel. This process allows parties to establish a shared secret key for symmetric encryption.\n\nAsymmetric encryption can also establish secure connections between remote users and virtual private networks\n\n(VPNs) to ensure data privacy and security.\n\nBlockchain technology\n\nPage 6 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nAsymmetric encryption is a cornerstone of blockchain technology and contributes significantly to the security and\n\nintegrity of cryptocurrency transactions. It helps ensure that only intended recipients can access assets by\n\nmanaging identities through public and private keys and verifying transaction authenticity with digital signatures.\n\nAsymmetric encryption can also secure smart contracts, which are self-executing contracts with terms directly\n\nwritten into code. Public and private keys encrypt and authenticate interactions within these contracts, ensuring\n\nthat only the intended recipients can execute the contract and enforce the terms.\n\nThe rise of quantum computing threatens traditional encryption methods. Quantum computers could break some\n\nasymmetric encryption algorithms, such as RSA and ECC, by running powerful quantum algorithms like Shor's\n\nalgorithm.\n\nDeveloped by mathematician Peter Shor in 1994, Shor's algorithm is the first quantum algorithm to efficiently\n\nfactor large integers and solve the discrete logarithm problem—critical components of many encryption schemes.\n\nA sufficiently powerful quantum computer running Shor's algorithm could easily break these encryption systems,\n\npotentially rendering all major public-key encryption systems currently in use obsolete.\n\nWhile quantum computers are still relatively experimental, many organizations are preparing for the future by\n\nturning to quantum-safe cryptography, also known as post-quantum cryptography (PQC). A recent study found\n\nthat more than half of organizations have started to replace their current encryption with PQC.2\n\nIn 2016, NIST launched an open competition to evaluate and standardize PQC algorithms. Its goal was to identify\n\nand endorse a suite of quantum-resistant algorithms to replace vulnerable cryptosystems.\n\nIn July 2022, NIST announced the top algorithms for PQC standardization, with IBM playing a role in developing\n\nthree of the four selected algorithms: CRYSTALS-Kyber, Falcon and CRYSTALS-Dilithium.3 NIST expects to\n\nfinalize its selection sometime in 2024.\n\nAlongside the looming threat of quantum computing, the rise of artificial intelligence (AI) has also dramatically\n\nchanged the encryption landscape.\n\nAI presents significant challenges to traditional encryption algorithms, mainly through its ability to improve\n\npattern recognition and accelerate brute-force attacks, which involve hackers systematically trying encryption\n\nkeys until they discover the correct one.\n\nStrong encryption algorithms historically take far too long to break with brute-force methods. However, advanced\n\nAI models can now analyze encrypted data to find vulnerabilities faster than ever, making specific encryption\n\nalgorithms less secure.\n\nAt the same time, however, advancement in AI holds the potential to vastly improve asymmetric encryption.\n\nSome of these potential benefits include:\n\nReal-time cryptosystem threat detection: AI and machine learning can help predict and identify potential\n\nsecurity breaches in real-time, allowing for proactive measures to protect cryptosystems.\n\nPage 7 of 8\n\nhttps://www.ibm.com/think/topics/asymmetric-encryption\n\nEnhanced encryption algorithms: AI can analyze large datasets to help identify and rectify weaknesses in\n\nexisting encryption methods.\n\nImproved key management: AI-driven systems can optimize key management by automating the process\n\nof generating, distributing and rotating encryption keys.\n\nLeveraging homomorphic encryption: Homomorphic encryption allows organizations to perform\n\ncomputations on encrypted data without requiring decryption. This approach means that organizations can\n\nuse sensitive data for AI model training and analysis without compromising confidentiality or privacy.\n\nSource: https://www.ibm.com/think/topics/asymmetric-encryption\n\nPage 8 of 8",
	"extraction_quality": 1,
	"language": "EN",
	"sources": [
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	],
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