As can be seen in the above implementation I wrote, the six steps to go from private key to ethereum address can be summarized as follows:. In addition to the open-ssl library referenced in the article that tayvano noted, other libraries that can be used to calculate elliptic curve public addresses include the ecdsa Python library , and Bitcoin's secpk1 library written in C although the latter will contain tools for formatting bitcoin addresses which are totally different than ethereum addresses due to the formatting steps and different hash algorithms and encoding methods, even if the underlying private key and public key are the same, as an example.
Note: Finally, it's important to have tests in place to make sure that an address generated is not only valid, but that the underlying private key used in the process will be valid to sign transactions i. Example : One such address verification checksum tool from the eth-keys library is the following command: keys. This is why using existing libraries may be safer, than writing the code from scratch. The last 40 characters of this string prefixed with 0x becomes the final Ethereum address.
Note: For a more detailed but simple mathematical explanation of these stepts please read this very useful article. If you want to dive deeper into the concept, read this book. Sign up to join this community. The best answers are voted up and rise to the top.
Stack Overflow for Teams — Start collaborating and sharing organizational knowledge. Create a free Team Why Teams? Learn more. How are ethereum addresses generated? Ask Question. Asked 5 years, 11 months ago. Modified 2 months ago. Viewed k times. Improve this question. Achala Dissanayake 5, 15 15 gold badges 24 24 silver badges 38 38 bronze badges.
I don't agree about the duplicate. Question is not about verifying if the address is valid but rather how the address is built and if it follows a format or is just random. Indeed it's not random but the result of some processes. The fact that the word "valid" is in the question is not a criteria, you won't mark all questions with the "valid" word as duplicates! Here we go. Might be worth keeping the comments pointing to possible dupes as they have value in offering a different perspective to those of us doing the learning.
Add a comment. Sorted by: Reset to default. Highest score default Date modified newest first Date created oldest first. Generating private key The private key is 64 hexadecimal characters. Definitions Address: An Ethereum address represents an account. Improve this answer. However, I don't know the specific reason. Would make for a great new question though.
It's unlikely you will get a real answer here. Good info - But didn't explain final optional checksum for capital letters like you did here. It says here: ethdocs. Show 3 more comments. Community Bot 1. Nicolas Massart Nicolas Massart 6, 2 2 gold badges 26 26 silver badges 62 62 bronze badges. A few quick questions: 1 The private and public keys: what encryption algorithm is used?
Is it the same as for bitcoin? What hashing function is used? Yes and yes but with keccak But you should ask this in another question and mark this one as answered if you consider the initial question is answered. It was actually these questions in the comment that I wanted answered how the address is generated, what algorithms etc.
If you add it to the answer I'll mark it as answered! I will clarify my original question somewhat. It's hard to answer clearly to questions that are not even asked. Link only questions are not encouraged. Show 1 more comment. Private Key Space: Here are some code examples, based on the elliptic curve secpk1 used by ethereum, as others have noted in order for the bit key to be valid, it must be smaller than the curve's parameter n which is also a bit value which can be written in hexadecimal format as: 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd Error-checking: Various libraries will produce errors if you try to feed a private key into them that is greater than n , as an error-checking mechanism i.
Related curve parameters: We can call the private key s to denote it as a secret exponent, as this value wraps around the curve using the parameter g using scalar multiplication which denotes a public generator point which is like a universal constant that everyone knows and uses, in order to generate their public key from s. Cryptographically-secure key derivation: The way that s is selected also matters immensely in terms of its cryptographic security.
Convert hex string generated in step 1 into a bytes b"" object. Calculate the public key as hex using the private key bytes object created in step 2. Convert the hex public key generated in step 3 into a bytes object. Desktop applications if you prefer to manage your funds via macOS, Windows or Linux. There are lots of different wallets to choose from. We want to help you choose the best one for you. Or a wallet with fraud alerts and withdrawal limits. Centralized exchanges will link your wallet to a username and password that you can recover in a traditional way.
If that company is attacked or folds, your funds are at risk. Wallets will often give you a seed phrase that you must write down somewhere safe. If you use a web wallet, bookmark the site to protect yourself against phishing scams. ETH is the native crypto of Ethereum. Dapps are applications built on Ethereum. Skip to main content. Help update this page. Translate page.
See English. No bugs here! Don't show again. What is ether ETH? Use Ethereum. Search away! Ethereum wallets The key to your digital future Wallets give access to your funds and Ethereum applications. Only you should have access to your wallet. Find a wallet. What's an Ethereum wallet?
Your Ethereum account Your wallet is your window into your Ethereum account — your balance, transaction history and more. Your login for Ethereum apps Your wallet lets you connect to any decentralized application using your Ethereum account. Wallets, accounts, and addresses It's worth understanding the differences between some key terms.
An Ethereum account is an entity that can send transactions and has a balance. Types of wallet Physical hardware wallets that let you keep your crypto offline — very secure. Get a wallet There are lots of different wallets to choose from. Crypto curious? Crypto converted? We can help you choose your wallet based on the features you care about. How to stay safe Wallets require a bit of a different mindset when it comes to safety.
Take responsibility for your own funds Centralized exchanges will link your wallet to a username and password that you can recover in a traditional way. Write down your seed phrase Wallets will often give you a seed phrase that you must write down somewhere safe.
The leading byte has either the value 0x02 if the y value is even as in this example , or the value 0x Since the compressed format does not contain the y coordinate, this cannot be used to directly infer the Ethereum address, or if it is done anyway, it will result in a wrong address indirectly, of course, it would be possible since the y coordinate can be derived from a compressed public key.
The uncompressed format of the public key can be obtained, e. The uncompressed format consists of a leading marker byte with the value 0x04 followed by the x and y coordinates. So if the leading marker byte is removed, just the data according to step 1 is obtained, which is needed for the derivation of the Ethereum address:. Steps 2 and 3 are performed by Keys. This allows the Ethereum address to be obtained using the uncompressed public key as follows:.
If the uncompressed key is given as byte , e. Alternatively, the byte can be converted to a BigInteger with the marker byte removed:. One thing to note here is that Keys. This can be relevant e. If Keys. Stack Overflow for Teams — Start collaborating and sharing organizational knowledge.
Create a free Team Why Teams? Collectives on Stack Overflow. Learn more. Asked 1 year, 3 months ago. Modified 4 months ago. Viewed 1k times. Andrew Andrew 1 1 silver badge 9 9 bronze badges. Add a comment. Sorted by: Reset to default. Highest score default Date modified newest first Date created oldest first. Ethereum addresses are derived as follows: Step 1: The 32 bytes x and y coordinate of the public key are concatenated to 64 bytes where both the x and y coordinate are padded with leading 0x00 values if necessary.
Step 2: From this the Keccak hash is generated. Step 3: The last 20 bytes are used as the Ethereum address. Step 1: In the posted question, the expressions Sign. When the results of both expressions are displayed with: System. So if the leading marker byte is removed, just the data according to step 1 is obtained, which is needed for the derivation of the Ethereum address: System.
This allows the Ethereum address to be obtained using the uncompressed public key as follows: System. Topaco Topaco Thanks, this is a great answer! Popular blockchains have hundreds of millions of transactions which include some of the most popular -- Bitcoin, Waves, Ripple, ZCash, Monero and Ethereum.
Currently, on the Ethereum blockchain there are million transactions  across 47 million  key pairs. The chance of generating a private key already used on the blockchain is around 1 in 2 — all but impossible. In this paper we examine how, even when faced with this statistical improbability, ISE discovered private keys as well as their corresponding public keys that committed 49, transactions to the Ethereum blockchain.
This paper focuses on our discovery of private keys used to commit Ethereum blockchain transactions. However, instead of attempting to brute force search random private keys, we devised ways to discover keys that may have been generated using faulty code, faulty random number generators, or a combination of both. The following sections outline how an Ethereum address is generated and our approach to discover those private keys that were generated in suboptimal ways.
The bit private key is used to compute a point on the secpk1 ECDSA curve to generate the public key. The public key is then hashed using keccak That hash is truncated to the lower bits to produce the public Ethereum address. The Ethereum address cannot be reversed back into a public key, nor can the Ethereum address be used in any way to derive the underlying private key that was used to generate it. Figure 1 illustrates the workflow to derive an Ethereum address from a randomly generated bit private key.
Figure 1. Example flow of deriving an Ethereum address from a private key. Knowing this algorithm, the goal of our research was to find Ethereum addresses that could not have plausibly been generated by a correct implementation of the algorithm, or, that were correctly derived from non-random private keys. The Ethereum blockchain allows anyone to query an address for information  , such as balances, transfers, and committed transactions.
This is done by querying an Ethereum node which can be run locally or remotely. Or for ease of use, several online services encapsulate the underlying data via web interfaces. One such tool, Etherscan , can be used to query the public Ethereum address from the above example:.
Figure 2. However, as the key is now disclosed in this paper, the address is public and may have since then been used for transactions. This key and Ethereum address should no longer be used for performing Ethereum transactions! With nearly 50 million public Ethereum addresses having recorded transactions on the Ethereum blockchain, it is likely that we may encounter keys that are weak or lack randomness, due to several possible factors.
An obvious one is key truncation. In an experiment, we picked a private key of 1, for no reason other than that it is the lower bound of a possible private key for secpk1 and it also lies within the 1 to 2 32 -1 range of a bit truncated key. We use the private key 0x to derive the public Ethereum address 0x7e5fad5dfcb7b8cbdf. As previously discussed, recall the infinitesimal probability of two Ethereum users generating the same private key—assuming at least one user is generating them randomly.
Instead, using Etherscan. Figure 3. ISE revealed that there are transactions on an Ethereum address derived from a private key of 0x01, and no Ether currently stored at that address. Since a private key of 0x01 has approximately zero percent chance of occurring randomly, we must assume this value was either chosen on purpose or due to an error.
The following sections detail our search to understand and examine how widespread the generation of weak keys is in the Ethereum blockchain. Our research sought to locate Ethereum addresses based on the use of weak keys, and to examine how those addresses are used.
While it is improbable that a weak key would ever be generated under legitimate circumstances using the appropriate code paths, we hypothesized that weak private keys may still be generated by coding mistakes, or operating system, device, and execution environment errors, and that these issues are common.
Aside from key truncation, some other common mistakes that could weaken bit keys are:. Due to limited computing resources, it is not feasible to enumerate all keys even in a much smaller bit key space. So, instead we focus on the achievable: enumerating keys that would appear in a smaller bit subset of the bit private key.
This amounts to 4,,, private keys for which we will need to calculate the corresponding public Ethereum address for and query the blockchain. To perform bulk scanning of potential Ethereum addresses, it is impractical, and even abusive in terms of resource usage, to query an online service like Etherscan. Instead, we generated an in-memory hash map of all public Ethereum addresses and queried this in-memory data structure for each enumerated key.
On a local mid-range laptop this resulted in a performance of roughly 15, key generations and lookups per second, per CPU core, with the bottleneck being the ECDSA private to public key generation portion. We expected that the lower bit portion of the key space would be most likely to contain weak keys; to account for endianness, we also scanned the upper bit portion, and for thoroughness we tested each distinct section of the bit key space with a bit window which may yield keys.
To illustrate the regions we scanned, Figure 4, below, depicts each region we have identified for enumeration. While enumerating the bit key space of each region A through H we leave the remaining bits of the bit key set to 0x Figure 4. This gives us eight regions with a possible 2 32 -1 i.
Translating the region definitions into explicit private key ranges, we scanned and tested these key ranges for transaction activity on the Ethereum blockchain:. The above key space ranges, while making up an infinitesimal part of the bit key space, are some areas that private keys might exist in due to errors or other factors compromising randomness of a bit key.
The following section outlines our results for each of the eight key space ranges. We discovered 49, transactions spread over public keys for which we have the private key, with a total transfer amount of more than 32 Ethereum. The present-day balance across these keys was 0 Ethereum, however that balance is volatile since there are daily transfers in and out of those addresses.
Present day balances for other types of cryptocurrency across these public keys amounted to 60,, ERC  based tokens. Tokens exist on Ethereum via smart contracts. However, enumerating all ERC based transactions and the sum of those transactions is beyond scope of this research and may be included in follow up future work. The figure below, Figure 5, is a graphical depiction of the private keys we discovered that were used for blockchain transactions.
The y-axis is the value of a key at its corresponding group offset, and the keys are plotted from left to right in order of increasing Ethereum address. For example, in group A, the bulk of discovered keys existed below the or 0xFF boundary. Figure 5. For each group we list the key range scanned, number of keys found, number of total transactions, total amount for those transactions, and the combined present balance of the addresses.
Scanning this region of the key space yielded 8, transactions through private keys. The total value of transactions using these weak private keys was While transactions are common in this range, there is currently a balance of 0 ETH. Figure 7, below depicts private keys and their offset of this group. Figure 7. Group A. Groups B through G are merged into a single section since they only yielded 4 private keys that committed 29 transactions on the blockchain.
This result was not surprising as we expected to find a majority of our findings to be in either end of the bit key space via our narrow bit window. Interestingly, one key in these groups, key value of 0x0a in group B had an outgoing transfer to an address that currently holds 44, ETH, more on that later. Figure 9 illustrates these 4 keys and their respective offset of their color-coded group. Scanning this region of the key space yielded 40, transactions through private keys.
A random private key of 64 (hex) characters ( bits / 32 bytes) is generated first. A (hex) character (64 bytes) public key is then derived from the generated private key using Elliptic Curve Digital Signature Algorithm (ECDSA). Vanity-ETH is an open source generator using your web browser to generate Ethereum vanity addresses. You can get a custom ETH vanity address right now.